Method and Apparatus for Emboli Containment

ABSTRACT

A catheter for use in an emboli containment system includes a flexible elongate member having self-expanding sealing means mounted on its distal extremeity. This self-expanding sealing means can take any suitable form, such as a braided structure formed of a suitable shape memory material such as a nickel titanium alloy. In order to prevent abrasion of a vessel, it is desirable to cover the braided structure with a covering of a suitable material such as a polymer which extends over the braided structure and which moves with the braided structure as it expands and contracts.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 08/813,023,filed on Mar. 6, 1997, now U.S. Pat. No. 6,270,477 which is acontinuation-in-part of application Ser. No. 08/650,464 filed on May 20,1996, now abandoned, the entirety of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

The present invention generally relates to medical devices, and inparticular, to catheters which can be used in an emboli containmentsystem. This invention also relates to an apparatus and method fortreating occluded vessels in living bodies and more particularly ballooncatheters and balloon guide wires for treating occlusions in vessels inhuman bodies, as for example carotid arteries.

Balloon angioplasty, and other transluminal medical treatments, arewell-known, and have been proven efficacious in the treatment ofstenotic lesions in blood vessels. The application of such medicalprocedures to certain blood vessels, however, has been limited, due tothe risks associated with creation of emboli during the procedure. Forexample, angioplasty is not the currently preferred treatment forlesions in the carotid artery, because of the possibility of dislodgingplaque from the lesion, which can enter the various arterial vessels ofthe brain and cause permanent brain damage. Instead, surgical proceduresare currently used, but these procedures present substantial risks.

One solution to this problem is the use of a multi-catheter embolicontainment system, as disclosed in the above-referenced applicationSer. No. 08/650,464. As disclosed therein, a treatment chamber within ablood vessel is formed by two occlusion balloons on opposite sides of astenotic lesion, thereby preventing emboli migration during thetreatment procedure. The chamber is created by two occlusion ballooncatheters which are slidably disposed with respect to one another.

Emboli containment procedures of this type are advantageous, becausethey permit the clinician to utilize the benefits of transluminaltreatment in a wider variety of blood vessels. However, the proceduresrequire the complex coordination of multiple catheters. Consequently, itis desirable to have catheters which make it easier for the clinician toutilize an emboli containment system. It is also desirable that thecatheters used in the emboli containment system have a high degree offlexibility, to navigate tortuous blood vessel networks.

Consequently, there exists a need for improved emboli containmentcatheters. This is especially true in the context of the “main”catheter, through which other catheters are inserted and controlled toform the emboli containment system. There is also a need for new andimproved apparatus and methods which make it possible to treat occludedvessels without endangering the patient.

SUMMARY OF THE INVENTION

The present invention advantageously provides as a main catheter anocclusive device adapted for use in a multi-catheter emboli containmentsystem. In one aspect of the present invention, there is provided acatheter, comprising an elongate flexible tubular body having a proximalend and a distal end. The tubular body incorporates a metallic member,which may comprise a braid or a coil. A main lumen and an inflationlumen extend through the tubular body, and are in a side-by-sideconfiguration. The main lumen is sized to receive a therapeutic and/ordiagnostic device such as a balloon angioplasty catheter or anatherectomy catheter. The tubular body is provided with a manifold. Themanifold has an aspiration port which is in fluid communication with themain lumen. The distal end of the tubular body also has a tip formed ofa more flexible material than that used to form the tubular body.

In one preferred embodiment, an inflatable balloon is mounted on thedistal end of the tubular body. An inflation port is also provided onthe manifold in this embodiment. The inflation port is in fluidcommunication with the inflation lumen. In this embodiment, theinflatable balloon is formed of a block copolymer ofstyrene-ethylene-butylene-styrene.

In another preferred embodiment, the metallic braid or coil is formed ofa metal selected from the group consisting of 304, 316, or 400 seriesstainless steel, nitinol, i.e., a nickel titanium, sometimes referred toherein as “Nitinol”, platinum, gold, Elgiloy®, or combinations thereof.Where a metallic braid is used, it may optionally have a braid densityat a first point on the tubular body that is greater than the braiddensity of the metallic braid at a second point on the tubular body byat least 20 picks per inch. Similarly, where a metallic coil is used, itmay optionally have a coil density at a first point on the tubular bodythat is greater than the coil density at a second point on the tubularbody.

In another aspect of the present invention, there is provided a cathetercomprising an elongate flexible tubular body having a proximal end and adistal end. Alternatively, there may be provided a circularcross-sectional configuration at the proximal end which is continuouswith a distal end having a reduced internal and outer tubular bodydiameters. A first and second lumen extend through the tubular body fromthe proximal end to the distal end in a side-by-side configuration. Thefirst lumen has a generally circular cross-sectional configuration atthe proximal end and a generally oval cross-sectional configuration atthe distal end. The second lumen has a diameter no smaller than 0.05inches, preferably no smaller than 0.08 inches, and is adapted toslidably accommodate a therapeutic or diagnostic device.

In one preferred embodiment, an inflatable balloon is mounted on thedistal end of the tubular body. The inflatable balloon is in fluidcommunication with the first lumen, such that fluid passing through thefirst lumen may be used to inflate or deflate the inflatable balloon.The second lumen size may vary in certain embodiments, such that in oneembodiment, the second lumen has a diameter no smaller than about 0.05inches, and is preferably no less than 0.080 inches.

In another aspect of the present invention, there is provided a catheterwith variable stiffness, comprising a tubular body having a proximal endand a distal end. A metallic braid or metallic coil is within thetubular body. In one embodiment, the proximal end of the tubular bodyhas a lower braid or coil density than the distal end. In anotherembodiment, the braid or coil density is kept constant along the lengthof the tubular body, and the tubular body is formed of materials withgreater stiffness at the proximal end. In another embodiment, acombination of braids and coils of varying density can be used atvarious points along the tubular body, to create a catheter tubular bodyhaving a more flexible distal end.

In another aspect of the present invention, there is provided a methodof making a catheter tubular body. The method comprises providing afirst polymeric tube formed of a first material having a first meltingpoint. The first polymeric tube is then inserted into a second polymerictube to form a combined tube. The second polymeric tube is formed of asecond material having a second melting point which is less than thefirst melting point. The combined tube is then placed adjacent to athird tube. The third tube is formed in part of the second material. Thetubes are then heated to a temperature greater than the second meltingpoint but less than the first melting point, such that the combined tubemelt fuses with third tube to form a catheter tubular body having twolumen extending therethrough in a side-by-side configuration. The firstmaterial may be selected from the group comprising polyimide, polyamide,PET and polyetheretherketone (referred to herein as “PEEK”), blendsthereof and the second material may be selected from the groupcomprising PEBAX®, polyethylene, nylon, or HYTREL® or blends thereof.Preferably, the temperature of the heating step is from about 250° to600° F. It is also preferred that the third tube incorporate a metallicmember, such as a braid or coil.

In general, it is an objection of the present invention to provide anapparatus or an assembly and method which can be used with approveddiagnostic and therapeutic devices while minimizing the opportunitiesfor emboli to migrate downstream.

Another object of the present invention to provide an apparatus orassembly and method of the above character which makes it possible toperform therapeutic procedures without using perfusion.

Another object of the invention is to provide an apparatus or assemblyand method of the above character in which the proximal balloon utilizedis a balloon carried by a guide wire.

Another object of the invention is to provide an apparatus or assemblyand method of the above characters in which the inflation fittingcarried by the proximal extremity of the balloon-on-a-wire is removableso that catheters can be slid over the wire without removal of the wirefrom the site in which it is disposed.

Another object of the present invention is to provide an apparatus orassembly and method for treating occluded vessels of the above characterwhich makes it possible to prevent downstream flow of debris or emboli.

Another object of the invention is to provide an apparatus and methodwhich makes it possible to reverse the flow of blood in an occludedvessel during the time that a stenosis is being crossed.

Another object of the invention is to provide an apparatus and method ofthe above character in which a negative pressure is created within thevessel to reverse the flow of blood in the vessel.

Another object of the invention is to provide an apparatus and method ofthe above character in which it is only necessary to stop the flow ofblood in a vessel of a patient for a very short period of time.

Another object of the invention is to provide an apparatus and method inwhich a working space is provided in the vessel free of blood fortreatment of the stenosis.

Another object of the invention is to provide an apparatus and method ofthe above character in which material which is dislodged during thetreatment of the occlusion or stenosis is removed by suction.

Another object of the invention is to provide an apparatus and method ofthe above character in which blood is shunted around the working space.

Another object of the invention is to provide an apparatus and method inwhich a cutting device is utilized for treatment of the stenosis oratheroma in the vessel and in which the material removed from thestenosis or atheroma is aspirated out of the operating space.

Another object of the invention is to provide an apparatus and method ofthe above character in which the amount of material removed from thestenosis or atheroma can be precisely controlled.

Another object of the invention is to provide an apparatus and method ofthe above character which makes it possible to treat stenoses orocclusions in the vessel which are normally not accessible for surgicalprocedures.

Another object of the invention is to provide an apparatus and method ofthe above character which utilizes two spaced apart balloons to createthe working space in the vessel.

Another object of the invention is to provide an apparatus and method ofthe above character that can be utilized to create a working space in avessel having a bifurcation therein and in which the working spaceincludes the bifurcation.

Another object of the invention is to provide an apparatus and method ofthe above character which utilizes three spaced apart balloons to createthe working space in the vessel having a bifurcation therein.

Another object of the invention is to provide an apparatus and method ofthe above character which includes a control console for controlling theinflation of the blood flow pump.

Another object of the invention is to provide an apparatus and method ofthe above character which is particularly adapted for use with thecarotid vessels.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of an embodiment of the catheter of the presentinvention.

FIG. 2 is a cross-sectional view of catheter of FIG. 1 along lines 2-2.

FIG. 3 is a cross-sectional view of the catheter of FIG. 1 along lines3-3.

FIG. 4 is a longitudinal cross-sectional view of the distal end of thecatheter of FIG. 1.

FIG. 5 is an enlargement of the region circumscribed by lines 5-5 of thecatheter of FIG. 4.

FIG. 6 is an illustration of the catheter of the present invention asused in an emboli containment system.

FIG. 7 is a cross-sectional view of the emboli containment system ofFIG. 6 along lines 7-7.

FIG. 8 is a cross-sectional view of the emboli containment system ofFIG. 6 along lines 8-8.

FIG. 9 is a cross-sectional view of the emboli containment system ofFIG. 6 along lines 9-9.

FIGS. 10A-E illustrate the use of an embodiment of the catheter of thepresent invention in an emboli containment treatment procedure.

FIG. 11 is a side-elevational view partially in section showing thecatheter apparatus or assembly of the present invention for treatingoccluded vessels.

FIG. 12 is a cross-sectional view taken along the line 12-12 of FIG. 11.

FIG. 13 is a cross-sectional view taken along the line 13-13 of FIG. 11.

FIG. 14 is a cross-sectional view taken along the line 14-14 of FIG. 11.

FIG. 15 is a schematic illustration of how the catheter apparatus shownin FIG. 11 is deployed in a carotid artery.

FIGS. 16A-16E are illustrations showing the various steps utilized indeployment of the catheter apparatus in performing the method of thepresent invention in a vessel where a bifurcation is not present.

FIG. 17 is a side-elevational view partially in section of anotherembodiment of a catheter apparatus or assembly incorporating the presentinvention for treating occluded vessels using an atherectomy device.

FIG. 18 is a cross-sectional view taken along the line 18-18 of FIG. 17.

FIG. 19 is a cross-sectional view taken along the line 19-19 of FIG. 17.

FIG. 20 is a side-elevational view in section of the distal extremity ofanother embodiment of a catheter apparatus incorporating the presentinvention and utilized for delivering an expandable stent to a stenosis.

FIG. 21A is a schematic illustration showing the manner in which theapparatus of the present invention is utilized in connection withvessels of a patient in performing the method of the present invention.

FIG. 21B is an additional partial schematic illustration showinginterconnections in the catheter apparatus shown in FIG. 21A.

FIG. 22 is a plan view of another embodiment of a catheter apparatusincorporating the present invention.

FIG. 23 is a cross-sectional view taken along the line 23-23 of FIG. 22.

FIG. 24 is an end elevational view looking down the line 24-24 of FIG.22.

FIGS. 25A, B, C, and D are illustrations or cartoons showing the methodof the present invention being utilized with the apparatus shown in FIG.21 in a vessel having a bifurcation therein.

FIG. 26 is a side-elevational view of a main catheter incorporating thepresent invention.

FIGS. 26A and 26B are partial side-elevational views of the distalextremities showing alternative embodiments of the main catheter of thepresent invention incorporating, respectively, Judkins left shape andJudkins right shape in their distal extremities.

FIG. 27 is a cross-sectional view taken along the line 27-27 of FIG. 26.

FIG. 28 is a cross-sectional view taken along the line 28-28 of FIG. 26.

FIG. 29 is an enlarged partial cross-sectional view of the distalextremity of the catheter shown in FIG. 26.

FIG. 30 is a side-elevational view of the balloon-on-a-wire constructionincorporating the present invention.

FIG. 31 is a cross-sectional view taken along the line 31-31 of FIG. 30.

FIG. 32 is an enlarged cross-sectional view of the distal extremity ofthe construction in FIG. 30.

FIG. 33 is a cross-sectional view similar to FIG. 32 but showing adifferent embodiment utilizing a twisted dual core.

FIG. 34 is a cross-sectional view similar to FIG. 32 but showing the useof a twisted core.

FIG. 35 is a cross-sectional view of the proximal removable fitting ofthe construction shown in FIG. 30.

FIG. 36 is a side-elevational view partially in cross section of anirrigation catheter incorporation the present invention.

FIGS. 36A and 36B are side-elevational views of the distal extremitiesof additional embodiments of irrigation catheters incorporating thepresent invention.

FIGS. 37-43 are cartoons showing the manner in which the apparatus ofthe present invention shown in FIGS. 26-36 is used performing atherapeutic procedure in accordance with the present invention.

FIG. 44 is a side-elevational view partially in cross-section of anotherembodiment of a main catheter incorporating the present invention.

FIG. 45 is a side-elevational view partially in cross-section showinganother embodiment of an irrigation catheter incorporating the presentinvention.

FIGS. 46-50 are cartoons showing the manner in which a therapeuticcarotid procedure is performed in accordance with the present inventionwhere there is a bifurcation.

FIG. 51 is a side-elevational view partially in section of anotherembodiment of a balloon-on-a-wire incorporating the present invention.

FIG. 52 is a cross-sectional view taken along the line 52-52 of FIG. 51.

FIG. 53 is a side-elevational view in section of another embodiment of acatheter apparatus incorporating the present invention for treatingoccluded vessels.

FIG. 54 is a side-elevational view in section similar to FIG. 53 butshowing the apparatus in FIG. 53 with the self-expandable sealing meansdeployed.

FIG. 55 is a side-elevational view in section of another embodiment of acatheter apparatus incorporating the present invention for treatingoccluded vessels.

FIG. 56 is a view similar to FIG. 55 but showing the self-expandablesealing means deployed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, there is depicted an embodiment of the ballooncatheter of the present invention. Although illustrated and describedbelow in the context of an emboli containment system featuring balloondilatation treatment of a stenotic lesion, it is to be understood thatthe present invention can be easily adapted to a variety of embolicontainment treatment applications. For example, the present inventorscontemplate that the catheter of the present invention can be used inemboli containment treatment procedures which include atherectomy, stentimplantation, drug delivery, as well as other applications. Furthermore,although depicted and described as a two lumen catheter, it should beappreciated that the present invention may also be adapted to cathetershaving more than two lumen. The manner of adapting the present inventionto these various treatments and structures will become readily apparentto those of skill in the art in view of the description which follows.

Catheter 10 generally comprises an elongate flexible tubular body 16extending between a proximal control end 12 and a distal functional end14. Tubular body 16 has a main lumen 30 which extends between ends 12and 14. Main lumen 30 terminates in a proximal opening 23 and a distalopening 27. A smaller inflation lumen 32, configured in a side-by-siderelationship with main lumen 30, extends along the length of tubularbody 16 and may terminate within or near an occlusion balloon 26 mountedon the distal end 14 of catheter 10, as described below. Inflation lumen32 is in fluid communication with balloon 26, such that fluid passingthrough inflation lumen 32 may be used to inflate or deflate balloon 26.In some embodiments, the inflation lumen may originate at a point distalto the proximal end 12, and extend distally from that point in aside-by-side configuration with main lumen 30.

In some embodiments, instead of an occlusion balloon 26, distal end 14is provided with a mechanical occlusive device such as a pull-wireactivated braid which filters all particles larger than 12 microns.Alternatively, other occlusive filtering devices may also be used, as isknown by those of skill in the art.

A control manifold 19 is provided at the proximal end 12 of catheter 10.Control manifold 19 is generally provided with a number of ports toprovide access to the catheter lumen. For example, for the embodimentdepicted in FIG. 1, control manifold 19 is provided with a catheterend-access port 22 and a catheter side-access port 24, to provide anintroduction point for the insertion of other catheters into lumen 30.Ports 22 and 24 are preferably provided with standard Touhy Borstconnectors, although other sealing type connectors, such as a hemostasisvalve, may be used. Manifold 19 is also provided with an aspiration port20 which is in fluid communication with lumen 30, for attachment ofdevices to aspirate fluid into opening 27, through lumen 30, and outport 20. An inflation port 18, in fluid communication with lumen 32, isfurther provided on manifold 18 for attachment of devices to inflate ordeflate balloon 26. In one preferred embodiment, ports 18 and 20 areprovided with standard luer connectors, to facilitate attachment ofstandard inflation or aspiration apparatus, respectively, to ports 18and 20. Other embodiments of catheter 10 may feature more or less ports,depending upon the number of lumen in the catheter and the desiredfunctionalities of the catheter.

Manifold 19 is preferably formed out of hard polymers or metals, whichpossess the requisite structural integrity to provide a functionalaccess port to the catheter lumen, such as for balloon inflation orfluid aspiration. In one preferred embodiment, manifold 19 is integrallyformed out of medical grade polycarbonate. Other suitable materials maybe used to form manifold 19, such as polyvinyl chloride, acrylics,acrylonitrile butadiene styrene (ABS), nylon, and the like.

Manifold 19 is attached to tubular body 16 so that the various ports areplaced in communication with the appropriate lumen, as described abovein connection with FIG. 1. Preferably, a strain relieving connector 11is used to join manifold 19 to tubular body 16. For the embodimentdepicted in FIG. 1, strain relieving connector 11 consists of a lengthof flexible polymeric tubing, such as 40 durometer (D) PEBAX®, or otherpolyether block amides, and other similar materials. Tubular body 16 isinserted in one end of strain relieving connector 11, and the other endof strain relieving connector 11 is inserted into manifold 19. Suitableadhesives, such as a cyanoacrylate, epoxies, or uv curable adhesives,may be used to bond manifold 19 to strain relieving connector 11.Alternately, manifold 19 may also be insert molded with the tubular body16, as is known by those of skill in the art. Adhesives may also be usedto bond the strain relieving connector 11 to tubular body 16, oralternately, conventional heat bonding, as known to those of skill inthe art, may be used to attach tubular body 16 to strain relievingconnector 11.

The length of tubular body 16 may be varied considerably depending uponthe desired application. For example, where catheter 10 is to be used aspart of an emboli containment system for treatment of carotid arterydisease, with catheter 10 being introduced at the groin, the length oftubular body 16 may range from 80 to 110 centimeters, and is preferably95 cm. Other treatment procedures, requiring a longer or shorter tubularbody 16, are easily accommodated by the present invention, by forming atubular body 16 of the desired length during the manufacturing process.

The outer diameter of tubular body 16 may also be varied considerably,and in most cases, will depend upon the intended treatment procedure forwhich catheter 10 will be used. That is, the outer diameter of tubularbody 16 must be large enough to be capable of forming a main lumen 30which can slidably accommodate the other catheters used in the embolicontainment system, as described in detail below. However, the outerdiameter of tubular body 16 must also be smaller than the internaldiameter of smallest blood vessel through which catheter 10 passesduring the selected treatment procedure. In general, the diameter ofmain lumen 30 may range from at least about 0.05 inches to about 0.12inches, and be capable of accommodating many types of catheters to beused therein, while still maintaining a low profile for the diameter oftubular body 16.

For many treatment applications, it has been found that a tubular bodyhaving an outside diameter of no more than about 0.135 inches (10French) is preferred. Advantageously, with an outer diameter of thissize, main lumen 30 may have an internal diameter of about 0.10 inches,making lumen 30 capable of accommodating a wide variety of treatmentcatheters, or catheters used for diagnostic purposes. Of course, as willbe appreciated by those of skill in the art, where the cathetersintended to be inserted into lumen 30 are known to have outer diameterssignificantly smaller than 0.10 inches, such that lumen 30 may besmaller than 0.10 inches and still accommodate them, a tubular body 16having an outer diameter of less than 0.135 inches may be selected.

Although not required, the interior surface of lumen 30 may be providedwith a liner 35 formed of a lubricous material, to reduce the frictionalforces between the lumen surface and the catheters which are insertedinto lumen 30. In one preferred embodiment, liner 35 is formed out ofpolytetrafluoroethylene (referred to herein as “PTFE”). Lubricousmaterials other than PTFE, which are biocompatible, fairly flexible, andeasily mounted to other polymeric materials of the type used to formcatheter tubular bodies, may also be used to form liner 35. Examples ofsuch materials include polyethylene, PEBAX®, nylon, and the like. Whereincreased flexibility of the distal end 14 of catheter 10 is desired,PEBAX® may be used in place of PTFE along a selected portion of distalend 14, such as the distal most 15-20 cm of end 14.

To minimize the outer diameter of tubular body 16, it is preferable thatinflation lumen 32 be as small as possible in accordance with itsfunction. That is, inflation lumen 32 is preferably no larger thanrequired to provide sufficient fluid to balloon 26 for rapid inflation,or so that fluid may be quickly withdrawn from balloon 26 duringdeflation. For compliant expansion balloons of the type described below,inflation lumen diameters of from about 0.008 inches to about 0.018inches are satisfactory, with a diameter of about 0.014 inches beingpreferred for some applications.

Furthermore, in one embodiment, as illustrated in FIGS. 1-3, the outerdiameter of tubular body 16 just proximal to balloon 26 is minimized byproviding an inflation lumen 32 a with an oval cross-sectionalconfiguration, as illustrated in FIG. 3. Preferably, inflation lumen 32a has an oval cross-sectional configuration which extends proximallyfrom the proximal edge balloon 26 by a distance of at least 0.1 cm, morepreferably 1 cm, and optimally by a distance equal to the length oftubular body 16. For ease of manufacturing, the cross-sectionalconfiguration of lumen 32 at points further proximal to balloon 26 maybe generally circular, as illustrated in FIG. 2. Where the lumenconfiguration differs from proximal to distal end, as illustrated inFIGS. 2 and 3, a region of transition 33 is provided wherein the lumenconfiguration changes from circular to oval.

It will be appreciated by those of skill in the art that othercross-sectional configurations of lumen 32 a may be provided and stillfunction to reduce the profile of tubular body 16. For example,triangular, rectangular, or other non-oval cross sectionalconfigurations are easily adapted to lumen 32 a, and the manner ofincorporating such alternative cross-sectional configurations will bereadily apparent to those of skill in the art in view of the descriptionwhich follows.

A variety of different manufacturing methods may be used to alter thecross-sectional configuration of lumen 32, as will be appreciated bythose of skill in the art. In one preferred method, lumen 32 is formedof a polymeric tube, such as a polyimide tube, which has been compressedat one end so that it has the desired oval shape. The polyimide tube isthen inserted into a second tube formed of a material having a lowermelting point than polyimide, such as 72D PEBAX®. The combination isthen heat bonded to another tube defining main lumen 30, such as abraided PEBAX® tube, as described below. The heat bonding takes place ata temperature greater than the melting temperature of PEBAX®, but lessthan the melting temperature of polyimide, so that the PEBAX® tubes meltfuse to form the two lumen tubular body.

Alternately, the cross-sectional configuration, as well as thecross-sectional area of lumen 32, may also be altered by joining twoseparate polymeric tubes together to form a continuous inflation lumen32. One of the tubes, corresponding to the proximal end of catheter 10as shown in FIG. 3, may have a circular cross-sectional configuration.The second tube, corresponding to the distal end of catheter 10 as shownin FIG. 2, has an oval configuration. One end of a mandrel may beinserted into each of the tubes, and conventional heat bonding may beused to create the cross-sectional configuration transition. As before,the combined tube may then be heat bonded to a second tube defining mainlumen 30 to form tubular body 16.

As illustrated in FIG. 1, an inflatable balloon 26 is mounted on thedistal end 14 of catheter 10. In most applications where catheter 10 isto be used in an emboli containment treatment procedure, inflatableballoon 26 will function as an occlusion balloon, to prevent blood frompassing through the blood vessel distal of balloon 26. Thus, inflatableballoon 26 is preferably able to expand to fit a variety of differentblood vessel diameters. Accordingly, it is preferred that inflatableballoon 26 have a compliant expansion profile, tending to increase inradial diameter with increasing inflation pressure. To achieve this,balloon 26 may be made out of materials which impart such expansioncharacteristics, including elastomeric materials such as latex orsilicone. In one preferred embodiment, inflatable balloon 26 is formedout of a material comprising a block copolymer ofstyrene-ethylene-butylene-styrene, sold under the trade name C-FLEX®.Further details as to balloons of this type are disclosed in ourcopending application entitled PRE-STRETCHED CATHETER BALLOON, Ser. No.08/812,139, filed Mar. 6, 1997, now abandoned, the entirety of which isincorporated by reference.

Inflatable balloon 26 may be placed in fluid communication with lumen 32a via a fill hole (not shown) extending through tubular body 16 withinballoon 26, such that fluid may be introduced into lumen 32 throughinflation port 18 to inflate balloon 26. Alternately, lumen 32 a mayterminate within balloon 26, to provide the requisite fluidcommunication. Balloon 26 may be attached to tubular body 16 by anysuitable manner known to those of skill in the art, such as adhesives orheat bonding.

Tubular body 16 must have sufficient structural integrity, or“stiffness,” to permit catheter 10 to be advanced through vasculature todistal arterial locations without buckling or undesirable bending oftubular body 16. However, it is also desirable for tubular body 16 to befairly flexible near distal end 14, so that tubular body 16 may benavigated through tortuous blood vessel networks. Thus, in one preferredembodiment, tubular body 16 is made to have variable stiffness along itslength, with the proximal portion of tubular body 16 being less flexiblethan the distal portion of tubular body 16. Advantageously, a tubularbody 16 of this construction enables a clinician to more easily inserttubular body 16 into blood vessel networks difficult to reach by atubular bodies having uniform stiffness. This is because the stifferproximal portion provides the requisite structural integrity needed toadvance tubular body 16 without buckling, while the more flexible distalregion is more easily advanced into and through tortuous blood vesselpassageways.

In one preferred embodiment, variable stiffness along the length oftubular body 16 is achieved by forming a polymeric tubular body 16 whichincorporates along its length a variable stiffness metallic member. Themetallic member may comprise a braid or coil, and may have varying braiddensity or coil pitch at different points along the catheter tubularbody. For example, as shown in FIGS. 2 and 3, tubular body 16 may beprovided with a braid 36 incorporated into the wall structure of tubularbody 16. Referring to FIG. 1, to achieve variable stiffness, proximalregion A of catheter 10 is provided with a metallic braid 36 having alower braid density than that present in the metallic braid 36 a ofdistal region B. The lower braid density of proximal region A permitspolymer flow in between the braids during the formation of the tubularbody. Because the polymer is relatively stiffer than the braid, thelower braid density results in proximal region A being less flexible, or“stiffer”, than distal region B. In one preferred embodiment, the braiddensity of proximal region A varies from 60 to 80 picks per inch, whilethat of region B varies from 90 to 110 picks per inch.

As will be appreciated by those of skill in the art, metallic membersother than braids may be incorporated into tubular body 16 to createvariable stiffness. For example, a metallic coil may be introduced intotubular body 16. The coil may have different pitch along the length oftubular body 16, such that region A is provided with a coil having alower pitch than that present in region B. The manner of adapting acoil, and other metallic members, to the catheter tubular body in placeof a braid will become readily apparent to those of skill in the art inview of the description which follows.

The precise density of the braiding provided to regions A and B can bevaried considerably at the point of manufacture, such that cathetershaving a variety of different flexibility profiles may be created.Moreover, the braid density may be varied within catheter regions A andB as well, by providing a metallic braid which has a braid densitygradient along its length. For example, the most proximal part of regionA may be provided with a metallic braid 36 having a braid density ofabout 60 picks per inch, with the braid density increasing distally at acertain rate so that the final pick count is not more than 110 picks perinch at the distal end.

A variety of different metals, known to be ductile and shapeable intofine wires and flat ribbons, having a diameter of about 0.0005 inches toabout 0.005 inches for wires, or the same thickness for a ribbon, may beused to form the metallic braids 36 and 36 a or metallic coils. Forexample, stainless steel, platinum, gold and nitinol, or combinationsthereof are all suitable metals. In one preferred embodiment, braid 36is formed of stainless steel, and has a braid density which varies from70 picks per inch at the most proximal part of region A, to 100 picksper inch at the most distal part of region B.

Metallic braids 36 may be introduced into the structure of tubular body16 through conventional catheter forming techniques. For example,tubular body 16 may be formed by braiding over a 72D PEBAX® tube thathas a removable core mandrel in the internal diameter supporting thePEBAX® tube, and then inserting the braided tube into a 72D PEBAX® outertube at the proximal region A and a 35D PEBAX® tube at the distal regionB, so that the braid is sandwiched between the inner and outer tubes. Astainless steel support mandrel may be inserted into the removable coremandrel as additional support. A shaping container such as a fluorinatedethylene propylene (FEP) shrink tube is inserted over the outer PEBAX®tube, and the entire apparatus may then be placed in a hot box or ovenkept at a temperature slightly greater than the melting temperature ofthe PEBAX® tubes. The PEBAX® tubes will melt and fuse together, and oncecooled, will form a tubular body incorporating the metallic braid. Theshaping container and mandrels may then be removed and discarded.

In another embodiment, variable stiffness of tubular body 16 may beachieved by forming regions A and B of tubular body 16 out of polymericmaterials having differing degrees of stiffness. For example, one halfof an inner tube of 72D PEBAX® may be inserted into an outer tube of 35DPEBAX®, and the other half of the inner tube may be inserted into a 72DPEBAX® outer tube. The combination may then be heat fused, as describedabove. The 35D/72D PEBAX® combination forms a more flexible tubular bodythan the region 72D/72D PEBAX® combination. More or less flexiblematerials may be used as desired to alter the flexibility of theresulting tubular body. Furthermore, the flexibility of the variousregions of a tubular body formed in this manner may be varied further byincorporating a metallic member having either a uniform density, or avarying density, into the tubular body, as described above.

In another preferred embodiment, variable stiffness along the length ofthe tubular body may be achieved by using different metallic members inregions A and B. For example, proximal region A may be provided with amultilayer coil, while distal region B may be provided with a braid.Alternately, proximal region A may be provided with a metallic braid,while distal region B may be provided with a single layer coil. Asdiscussed above, the densities of the metallic members in the respectivesections may be varied considerably to select for a desired variablestiffness profile, as will be appreciated by those of skill in the art.

In one preferred embodiment, variable stiffness along the length of thetubular body is achieved by keeping the braid density constant along thelength of tubular body 16 and then forming the proximal and distalportions of tubular body 16 of polymeric materials of differingstiffness. For example, braid density may be uniform and range from60-80 picks/inch, more preferably be about 70 picks/inch, with region Abeing formed of 72D PEBAX® and region B being formed of 25-50D PEBAX®.Alternately, region A can be formed of high density polyethylene andregion B of low density polyethylene.

Moreover, any of a variety of different polymeric materials known bythose of skill in the art to be suitable for catheter body manufacturemay be used to form tubular body 16. For example, tubular body 16 may beformed out of PEBAX®, blends of Pebax™ and nylons, polyetheretherketone(PEEK), polyethylenes, and HYTREL®, and the like. Different materialsmight also be combined or blended to select for desirable flexibilityproperties.

Also, although tubular body 16 has been described in the context ofhaving two regions of differing flexibility, it will be readilyappreciated by those of skill in the art that three or more regions ofdiffering flexibility may easily be provided, by adapting the teachingscontained herein.

In the above-discussed embodiments, and all other embodiments of thepresent invention, it may be preferred to provide main lumen 30 and theouter surface of tubular body 16 with a hydrophillic coating, ahydrophobic coating, or combinations thereof. For example, main lumen 30may be provided with a hydrophobic coating, such as silicone, whiletubular body 16 is provided with a hydrophillic coating, such aspolyvinyl pyrrolidone (PVP), polyurethane blends, copolymers ofacrylonitrile, and the like. Other hydrophobic and hydrophilliccoatings, as known to those of skill in the art, may also be used. Inaddition, any of a variety of antithrombogenic coatings, such asheparin, may also be applied to the catheter of the present invention,alone or in combination with other coating types.

Referring to FIGS. 4 and 5, there is illustrated a cross-sectional viewof the distal end 14 of catheter 10. Distal end 14 is provided with asoft distal tip 50, which is not pre-formed with tubular body 16, but isinstead attached to tubular body 16 as a tube post manufacturing step.Distal tip 50 is preferably soft enough and flexible enough, so as tominimize trauma to body vessels as catheter 10 is advanced, and also tofacilitate navigation of catheter 10 in tortuous vessels. In onepreferred embodiment, distal tip 50 is formed as a 0.5 cm sleeve of25-40D PEBAX®, and is bonded to tubular body 16 by heat fusing.Alternately, distal tip 50 may be attached to tubular body 16 byadhesives, or by insert molding, as is known to those of skill in theart. Preferably, distal tip 50 is in alignment with tubular body 16, anddoes not bend or curve, such that the radial axis of distal tip 50 issubstantially the same as that of tubular body 16.

The distal end 14 of catheter 10 is also preferably provided with aradiopaque material 44. Advantageously, radiopaque material 44 serves asa marker to help the clinician position catheter 10 during a medicalprocedure. Various well-known radiopaque materials may be used in distalend 14, such as platinum, gold, and platinum-iridium blends. The fulllength, or part of the length of the tubular body, may also beradiopaque by blending radiopaque materials in the polymeric materialsused to form the body. Furthermore, radiopacity of the tip can also beachieved by loading (i.e., comparing) the distal tip 50 with asufficient amount of barium sulfate. Alternatively, bismuthsubcarbonate, bismuth trioxide or bismuth oxychloride may be used as aradiopaque filler. Also, radiopacity may be achieved by using radiopaquewire or flat ribbon to make the braid or coil.

Illustrated in FIGS. 6-9, there is an emboli containment systemutilizing catheter 10 of the present invention. Catheter 10 of thepresent invention is used in the treatment of a stenosis 55 in a lumen50 in a blood-carrying vessel 58 in which the stenosis 55 at leastpartially occludes the lumen 50. The emboli containment system depictedin FIG. 6 comprises a catheter 10, as described above, as well ascatheters 100 and 200.

Catheter 100 comprises an elongate flexible tubular body 116 havingproximal end and distal end 114. An inflatable balloon 126 of the sametype as inflatable balloon 26 is coaxially mounted on tubular body 116on the end 114 of catheter 100. The tubular body 116 has centrallydisposed inflation lumen 132 in fluid communication with balloon 126,such that fluid passing through lumen 132 may be used to inflate balloon126. Alternatively, fluid may be withdrawn from lumen 132 to deflateballoon 126. As shown in FIG. 6, catheter 100 is disposed within mainlumen 30 of catheter 10 and is slidably and coaxially mounted thereinfor variable displacement of balloon 126 with respect to the firstballoon 26, as hereinafter described. One preferred embodiment of acatheter 100 is disclosed in our co-pending application, entitled HOLLOWMEDICAL WIRES AND METHODS OF CONSTRUCTING SAME, Ser. No. 08/812,876,filed Mar. 6, 1997, now U.S. Pat. No. 6,068,623, the entirety of whichis incorporated by reference.

The emboli containment system also comprises catheter 200 comprising anelongate flexible tubular body 216 having proximal end and distal end214. Catheter 200 is also provided with a generally centrally disposedlumen 230 extending from the proximal end to the distal end of catheter200, and through which catheter 100 is coaxially and slidably mounted.

The distal end 214 of catheter 200 is provided with means for performinga medical procedure, such as an apparatus for treating stenotic lesion55. In the embodiment of the invention shown in FIG. 6, this meanscomprises a dilatation balloon 226, which is preferably a non-compliantinflatable balloon which is coaxially mounted on the distal end 214 ofcatheter 200. Balloon 226 may also be attached to tubular body 216 inthe same manner as balloons 26 and 126 hereinbefore described. Tubularbody 216 is provided with a balloon inflation lumen 232 which is influid communication with balloon 226, such that balloon 226 may beinflated by the passage of fluid through lumen 232.

The operation and use of the emboli containment system utilizing thecatheter of the present invention for treating occluded vessels may nowbe briefly described in connection with an occlusion formed by astenosis in a carotid artery, as illustrated in FIGS. 10A-E.

Catheter 100 is inserted into an incision into a femoral artery of apatient and is advanced through that artery into the aorta of thepatient and into the ostium of the carotid artery to be treated. Aftercatheter 100 has been introduced, catheters 10 and 200, with balloons 26and 226 completely deflated, are introduced over catheter 100 and areadvanced into the ostium of the carotid artery and into the lumen orpassageway of the vessel as shown in FIGS. 10A-E.

The emboli containment system is advanced until catheter 10 is proximalof a stenosis 55 in the vessel lumen 50 to be treated. Balloon 26 isthen inflated by introducing a suitable inflation medium such as aradiopaque liquid into port 18 to cause it to pass through the ballooninflation lumen 32 to inflate balloon 26, as shown in FIG. 10B. Balloon26 is progressively inflated until it engages the side wall 58 of thevessel to occlude the lumen 50.

Catheter 100 is then advanced through stenosis 55 as shown in FIG. 10C.Catheter 100 with deflated balloon 126 thereon is advanced throughstenosis 55 until the balloon 26 is distal of stenosis 55 as shown inFIG. 10D. Balloon 126 is then inflated by passing an inflation mediumthrough lumen 132 to the interior of the balloon 126 to inflate theballoon 126 until it engages the sidewall 58 of the vessel lumen 50. Assoon as the balloon 126 has been inflated, a working space is providedbetween balloons 26 and 126, so that medical procedures can beundertaken to remove or reduce the stenosis 55 in the space betweensecond balloons 26 and 126, without risk of unwanted particles or emboliescaping into the blood stream.

For emboli containment systems featuring balloon dilatation treatment,it is desired to compress the plaque or material forming the stenosis toprovide a larger vessel. Thus, catheter 200 is advanced over catheter100 to cause distal end 214 with balloon 226 thereon to be advanced intothe working space. As soon as balloon 226 has been properly positionedwithin stenosis 55, balloon 226 is inflated with a suitable inflationmedium, as for example a radiopaque liquid. Balloon 226 can be inflatedto the desired pressure to cause compression of the plaque of thestenosis 55 against the sidewall 58 of lumen 50 by the application ofappropriate inflation pressure. As in conventional angioplastyprocedures, balloon 226 can be formed of a non-elastic relativelynon-compliant material so that appropriate pressures, such as 10-15atmospheres, can be used within balloon 226 to apply compressive forcesto the vessel without danger of rupturing the vessel. It should beappreciated that the non-elastic capabilities can also be achieved by acomposite elastic material.

Once the clinician is satisfied that the occlusion forming stenosis 55has been sufficiently compressed, balloon 226 can be deflated. After theappropriate dilation of stenosis 55 has been accomplished, catheter 200can be removed from the stenosis. Moreover, in one preferred method,catheter 200 is completely withdrawn from the emboli containment system,and an irrigation catheter is inserted over catheter 100 and throughlumen 30, as described in our copending application entitled METHOD FOREMBOLI CONTAINMENT, Ser. No. 08/812,875, filed Mar. 6, 1997, now U.S.Pat. No. 5,833,644, the entirety of which is incorporated by reference.Fluid introduced into the working space may be removed by supplying anegative pressure or suction to aspiration port 20. This creates anegative pressure within space 30 a defined by the interior surface oflumen 30 and outer tubular body 216, to suck or aspirate blood or otherfluids in lumen 50 into space 30 a and out of aspiration port 20. Inthis manner, irrigation and aspiration of the working space may takeplace so that any plaque coming off the occlusion forming the stenosis55 can be aspirated out of the vessel. Subsequently, balloon 26 andballoon 126 can be deflated to permit normal blood flow through thevessel lumen 50. The entire catheter assembly can then be removed and asuture applied to the incision created to obtain access to the femoralartery.

In general, the catheter apparatus is for treatment of a stenosis in alumen in a blood carrying vessel. It is comprised of a main catheter anda balloon-on-a-wire device. The main catheter is comprised of a firstflexible elongate tubular member having proximal and distal extremities.A first inflatable elastic balloon having an interior is coaxiallymounted on the distal extremity of the first flexible elongate tubularmember. The first flexible elongate tubular member has a ballooninflation lumen therein in communication with the interior of the firstballoon. The first elongate tubular member has a main lumen thereinextending from the proximal extremity to the distal extremity andexiting through the distal extremity. An adapter is mounted on theproximal extremity of the first flexible elongate tubular member and hasa balloon inflation port in communication with the balloon inflationlumen, a therapeutic catheter port and an aspiration port incommunication with the main lumen. The balloon-on-a-wire device iscomprised of a guide wire having proximal and distal extremities.

A second inflatable elastic balloon has an interior and is coaxiallymounted on the distal extremity of the guide wire. The guide wire has aballoon inflation lumen therein in communication with the interior ofthe second balloon. The balloon-on-a-wire device is slidably mounted inthe therapeutic catheter port and in the main lumen of the firstelongate tubular member with the proximal extremity of the guide wirebeing disposed outside of the main lumen. Removable valve means iscarried by the proximal extremity of the guide wire and has thecapability of forming a fluid-tight seal with respect to the guide wirewhile permitting relative axial movement of the guide wire and the firstflexible elongate tubular member with respect to each other whereby thefirst balloon can be moved so that it is proximal of the stenosis andthe second balloon so that it is distal of the stenosis. The removablevalve means includes an inflation port in communication with the ballooninflation lumen and the guide wire. The apparatus is also comprised ofmeans coupled to the balloon inflation port of the first flexibleelongate tubular member for inflating the first balloon and meanscoupled to the balloon inflation port of the removable valve means forinflating the second balloon to create a working space which bracketsthe stenosis.

More particularly as shown in FIGS. 11-14, the catheter apparatus 311 ofthe present invention is for use in the treatment of a stenosis 312 in alumen 313 in a blood-carrying vessel 314 in which the stenosis 312 has alength and a width or thickness which at least partially occludes thelumen 313. The apparatus consists of a first elongate flexible tubularmember 316 formed of a suitable plastic material which is provided withproximal and distal extremities 317 and 318. A first balloon 319 ismounted on the distal extremity 318 and preferably is a compliantballoon formed of a suitable elastic material such as a latex or a verylow radiation polyethylene so that it can be inflated to the size of thevessel 314 in which it is to be disposed. Thus, the balloon 319 shouldbe capable of expanding to various diameters depending on the size ofthe vessel. The first balloon 319 can be formed as a separate balloonseparate from the elongate tubular member 316 as shown and adheredthereto by suitable means such as an adhesive (not shown), or it can beformed integral with the tubular member 16 in a manner well known tothose skilled in the art.

The tubular member 316 is provided with a large centrally disposed ormain lumen 321 extending from the proximal extremity 317 to the distalextremity 318. It is also provided with a balloon inflation lumen 322which has a distal extremity in communication with the interior of thefirst balloon 319 through a port 323. The proximal extremity of theballoon inflation lumen 322 is in communication with a balloon inflationfitting 324 mounted on the proximal extremity 317 of the tubular member316. The fitting 324 can be of a conventional type as for example aLuer-type fitting which is adapted to be connected to a ballooninflation device (not shown) for inflating and deflating the firstballoon 319.

The first tubular member 316 is also provided with an aspiration lumen326 which exits through the distal extremity 318 and the proximalextremity 317 of the tubular member 316. A Luer-type fitting 327 ismounted on the proximal extremity 317 and is in communication with theaspiration lumen 326. The fitting 327 is adapted to be connected to asuitable aspiration or suction source (not shown) of a conventional typesuch as a syringe or rubber bulb for aspiration purposes as hereinafterdescribed.

The catheter assembly or apparatus 311 also consists of a secondelongate flexible tubular member 331 having proximal and distalextremities 332 and 333. A second inflatable balloon 336 of the sametype as the first inflatable balloon is coaxially mounted on the distalextremity 333 in a conventional manner. The tubular member 331 isprovided with a large generally centrally disposed arterial blood flowlumen 337 which opens through the distal extremity 333 and is incommunication with a Luer-type fitting 338 which as hereinafterdescribed is adapted to be connected to a supply of arterial blood fromthe patient which for example can be taken from another femoral arteryof the patient by the use of a blood pump.

The second tubular member 331 is also provided with a balloon inflationlumen 339 which is in communication with the interior of the secondinflatable balloon 336 through a port 341. The proximal extremity of thelumen 339 is in communication with the Luer-type fitting 342 mounted onthe proximal extremity 332 of the second tubular member 31 and as withthe balloon inflation fitting 324 is adapted to be connected to aballoon inflation-deflation device (not shown) of a conventional type.The second tubular member 331 is also provided with a lumen 343 whichalso can be used as a guide wire and/or for introducing a salinesolution extending from the proximal extremity to the distal extremity.The lumen 343 is sized so that it is adapted to receive a conventionalguide wire 346 as for example a 0.014″or 0.018″ guide wire and extendsfrom the proximal extremity to the distal extremity so that the guidewire 346 can extend beyond the distal extremity of the second tubularmember 331. A fitting 347 is provided on the proximal extremity 332 incommunication with the lumen 343 for introducing the saline solution.

As shown in FIG. 11, the second tubular member 331 is disposed withinthe central lumen 321 of the first tubular member 316 and is slidablyand coaxially mounted therein for displacement of the second balloon 336with respect to the first balloon 319 as hereinafter described.

The catheter assembly or apparatus 311 also consists of a third elongateflexible tubular member 351 having proximal and distal extremities 352and 353. It is provided with a centrally disposed lumen 356 extendingfrom the proximal extremity 352 to the distal extremity 353 and throughwhich the second tubular member 331 is coaxially and slidably mounted.

Means 357 is provided on the distal extremity 353 of the third tubularmember 351 for performing a medical procedure. In the embodiment of theinvention shown in FIG. 11, this means 357 consists of a third balloon358 which can be non-compliant coaxially mounted on the distal extremityof the third tubular member 351. The third balloon 358 can be attachedin the same manner as the first and second balloons 319 and 336hereinbefore described. The third tubular member 351 is provided with aballoon inflation lumen 359 which has its distal extremity incommunication with the interior of the balloon 358 through a port 361.The proximal extremity of the balloon inflation 359 is in communicationwith a Luer-type fitting 362 provided on the proximal extremity 352 andadapted to be connected to a conventional inflation deflation device(not shown) for inflating and deflating the third balloon 358.

The operation and use of the catheter assembly or apparatus 311 in themethod of the present invention for treating occluded vessels may now bebriefly described in connection with an occlusion formed by a stenosisin a vessel not having a bifurcation therein as for example in saphenousgraft or in one of the right and left carotid arteries, also calledinternal and external carotid arteries, of a patient in connection withthe illustrations shown in FIGS. 15 and 16A-16E. A guiding catheter 363(FIG. 15) of a conventional type is inserted into an incision into afemoral artery 364 of a patient and is advanced through that artery intothe aorta of the heart 365 of the patient and into the ostium 366 of theselected carotid artery or vessel as for example the left carotid 367.

After the guiding catheter has been appropriately positioned, the guidewire 346 is introduced separately into the guiding catheter or alongwith the catheter assembly 311. The distal extremity of the catheterapparatus or assembly 311 with all of the first, second and thirdballoons 319, 336 and 358 completely deflated, is introduced into theguiding catheter 363 along with or over the guide wire 346 and isadvanced through the guiding catheter 363 into the ostium 366 of thecarotid artery or vessel 367 and into the lumen or passageway 368 of thevessel as shown in FIGS. 15 and 16B.

The distal extremity of the catheter assembly 311 is advanced until itis just proximal of a stenosis 369 in the carotid artery 367 to betreated. The balloon 319 is then inflated by introducing a suitableinflation medium such as a radiopaque liquid into the fitting 324 tocause it to pass through the balloon inflation lumen 322 through theport 323 and into the interior of the first balloon 319 to inflate thesame as shown in FIG. 16B. The balloon 319 is progressively inflateduntil it engages the side wall of the vessel 367 to occlude the vessel367. At the time that this is occurring, a negative pressure or suctionis applied to the aspiration fitting 327 to supply a negative pressurethrough the balloon inflation lumen 322 to suck or aspirate blood in thevessel 367 distal of the first balloon 319 into the aspiration lumen 326and out the aspiration fitting 327 to thereby reverse the flow of bloodthrough the stenosis as shown by the arrows 371 in FIG. 16B.

While a reverse flow of blood is occurring in the vessel 367, the guidewire 346 is advanced through the stenosis 369 as shown in FIG. 16C. Inthe event that any pieces or particles of plaque are knocked off of theocclusion formed by the stenosis 369 by movement of the guide wire 346through the same, such pieces of plaque or emboli will be drawn out withthe reverse flow of blood into the aspiration lumen 326 and out of theaspiration fitting 327. During the time that the guide wire 346 is beingadvanced through the stenosis 369 it may be desirable at the same timeto introduce a saline solution through the guide wire lumen 343 of thesecond elongate flexible tubular member 331 to exit through the distalextremity of the second elongate flexible tubular member 331 into thespace immediately proximal of the stenosis 369. This introduced salinesolution aids the flow of particulate or other particles dislodged fromthe stenosis 369 during advancement of the guide wire 346 through thesame and carries them back with the mixed saline blood solution throughthe aspiration lumen 326 in a manner hereinbefore described.

With the guide wire 346 remaining in position, the second elongateflexible tubular member 331 with the second balloon 336 thereon in adeflated condition is advanced over the guide wire 346 through thestenosis 369 until the second balloon 336 is distal of the stenosis 369as shown in FIG. 16D after which the second balloon 336 is inflated byintroducing an inflation medium as for example a radiopaque liquidthrough the inflation fitting 342 into the lumen 339 through the port341 to the interior of the second balloon 336 to inflate the secondballoon 336 until it engages the sidewall of the vessel 367.

Prior to, during or after inflation of the second balloon 336, the guidewire 346 can be removed. However, it is preferable to remove the guidewire 346 as soon as the second balloon 336 has been advanced so that itis beyond the stenosis 369. At this time, and certainly prior tocomplete inflation of the second balloon 336, blood is shunted acrossthe stenosis 369 and into the lumen 368 distal of the second balloon 336by introducing blood through the fitting 338 and into the centrallydisposed blood flow lumen 337 in the second tubular member 331 so thatit exits out the central lumen 337 distal of the second balloon 336. Theblood which is supplied to the fitting 337 can be taken from anotherfemoral artery of the patient and pumped into the fitting 338. Inaddition, if desired, the blood which is aspirated in the space distalof the first balloon 319 can be appropriately filtered and also suppliedto the fitting 338. By shunting blood past the stenosis 369 in thismanner it can be seen that blood is being continuously supplied to thecarotid artery of the patient during the time that the second balloon336 is inflated and occludes the lumen 368 in the vessel 367.

As soon as the second balloon 336 has been inflated, it can be seen thatthere is provided a working space 376 (FIG. 16D) between the first andsecond balloons 319 and 336 so that medical procedures can be undertakento remove or reduce the stenosis 369 in the space between the first andsecond balloons 319 and 336.

Assuming that it is desired to compress the plaque or material formingthe stenosis 369 to provide a larger lumen, opening or passagewaythrough the stenosis 369 the third tubular member 51 can be advanced bygrasping the proximal extremity 352 to cause the distal extremity withthe third balloon 358 thereon to be advanced into the working space 376.As soon as the balloon 358 has been properly positioned within thestenosis 369, the balloon 358 also can be inflated with a suitableinflation medium as for example a radiopaque liquid. The balloon 358 canbe inflated to the desired pressure to cause compression of the plaqueof the occlusion against the sidewall of the vessel 367 by theapplication of appropriate pressure. As in conventional angioplastyprocedures, the third balloon 358 can be formed of a non-elasticrelatively non-compliant material so that high pressures as for example10-15 atmospheres can be used within the balloon to apply compressiveforces to the vessel without danger of rupturing the vessel. It shouldbe appreciated that the non-elastic capabilities can also be achieved bya composite elastic material.

Since the blood flow has been restored to the vessel 367 by the shunthereinbefore described, the compression of the occlusion forming thestenosis 369 can be carried out for an extended period of time, as forexample after a few minutes, if desired to help ensure that a largelumen or passageway is formed through the stenosis 369 as shown in FIG.16E. If it is believed that the occlusion forming the stenosis 369 hasbeen sufficiently compressed, the third balloon 358 can be deflated. Inthe event an inelastic balloon is utilized for the third balloon 358,and it is desired to utilize a larger third balloon, this can beaccomplished by removing the third tubular member 351 with the deflatedballoon 358 thereon and introducing a third tubular member 351 having alarger size balloon thereon over the second tubular member 331 andadvancing it into the stenosis 369 and inflating the larger size balloonto create a still larger passage through the stenosis 369.

After the appropriate dilation the stenosis 369 has been accomplishedthe third balloon can be removed from the stenosis while aspiration ofthe working space 376 is still ongoing so that any plaque coming off theocclusion forming the stenosis 369 can be aspirated out of the vessel.After the third balloon 358 has been removed from the stenosis, thesecond balloon 336 and the first balloon 319 can be deflated to permitnormal blood flow through the vessel 367 after which the arterial bloodflow supply to the fitting 338 can be terminated. The entire catheterassembly 311 can then be removed from the guiding catheter 363 afterwhich the guiding catheter 363 can be removed and a suture applied tothe incision created to obtain access to the femoral artery.

In place of the third balloon 358 for causing compression of theocclusion forming the stenosis 367 to create a larger passagewaytherethrough, an atherectomy device 381 (see FIG. 17) can be utilizedfor operating in the working space 376 to remove the plaque of theocclusion forming the stenosis. This can be accomplished with a catheterassembly or apparatus 381 which in many respects is similar to theapparatus 311 shown in FIG. 11 and consists of a first tubular member316 with a first balloon 319 and a second tubular 331 with a secondballoon 336 thereon. In place of the third flexible elongate tubularmember 351 there is provided a third flexible elongate tubular member386 which is provided with proximal and distal extremities 387 and 388.The flexible elongate tubular member 386 is slidably and rotatablymounted in the central lumen 321 of the flexible elongate member 316 andis provided with a central or main lumen 389 through which the secondflexible elongate tubular member 331 extends. It is also provided with alumen 391 extending from the proximal extremity to the distal extremitythrough which a saline solution can be introduced for saline irrigationas hereinafter described. It is also provided with another lumen 392which is adapted to receive a plurality of electrical conductors 393 forperforming electrical ftunctions as hereinafter described. The lumen 392is connected to a conventional Luer-type fitting 396 serving as a fluidirrigation fitting mounted on the proximal extremity first tubularmember 312 and is in communication with an annular recess 397 which isin communication with the lumen 391 provided in the tubular member 386for supplying a saline irrigation liquid through the flexible elongatetubular member 386 and into the working space 376 provided between thefirst and second balloons 316 and 336. In order to aid aspiration of thesaline irrigation liquid from the working space 376, the outer surfaceof the flexible elongate tubular member 386 is provided with a helicalgroove 398 therein which has one end which opens into the working space376 and which has the other end in communication with the aspirationfitting 327.

Means is provided for rotating the second tubular member 386 andconsists of suitable means such as a spur gear 401 mounted on theproximal extremity 387 of the tubular member 386. The spur gear 401 isdriven in a suitable manner as for example by another smaller spur gear402 which is of greater width than spur gear 401 so as to provide asplined gear connection between the gears 401 and 402. This accommodatesthe desired longitudinal movement for the tubular member 386 so that thedistal extremity 388 of the tubular member 386 can be advanced andretracted in the working space 376 as hereinbefore described. Anelectrical drive motor 403 is provided for driving the gear 402.

Atherectomy means 406 is provided on the distal extremity 388 of theflexible elongate tubular member 386. As shown in FIGS. 17 and 19, theatherectomy means 406 consists of a flexible elongate member 407 formedof a suitable material such as stainless steel or preferably asuperelastic Nitinol. The flexible elongate member 407 is wound into ahelix as shown in FIG. 19 onto the distal extremity of the tubularmember 386. The flexible elongate member 407 can be formed of a ribbonhaving a thickness of 0.003″ and a width of 0.060″. One end of theflexible elongate member 407 can be secured to the tubular member 386,as for example by inserting the same into a slit 408 and additionally bythe use of adhesive (not shown). The flexible elongate member 407 iswrapped into a helix in a direction opposite to the direction of normalrotation of the tubular member 386 and can be provided with a specialtip 409 on its free end with the tip having an arcuate surface 411 thatis inclined rearwardly to terminate at a cutting edge 412 (see FIG. 19)which is adapted to engage the plaque or the stenosis 369.

When the distal extremity 388 of the flexible elongate tubular member386 has been introduced into the working space 376, the end or tip 409of the flexible elongate member 407 of the atherectomy means 406 isfree. A saline solution is introduced into the fitting 357. Thereafterthe motor 403 can be energized to cause rotation of the tubular member386 and to thereby cause rotation of the helically wound flexibleelongate member 407 to cause its free end or tip 409 to be movedoutwardly radially under centrifugal force to bring the cutting edge 412into engagement with the plaque 369 in the stenosis 369 to causeprogressive removal of the plaque forming the stenosis 369 to enlargethe passageway extending through the stenosis. Because of the roundedconfiguration of the tip 409, the tip 409 will not dig into the vesselwall but will only remove plaque which is engaged by the cutting edge412. As the plaque is being removed, the saline solution introducedthrough the fitting 396 into the space 376 picks up the plaque particlesor emboli as they are being removed. The saline solution with the plaqueor emboli therein is removed through the spiral groove 398 and throughthe aspiration port 327. The flexible elongate tubular member 386 can bemoved back and forth so that the cutting tip 409 engages the length ofthe stenosis 369 so that substantially all of the stenosis 369 can beremoved.

Means is provided to sense when sufficient plaque has been removed fromthe stenosis 369 and to ensure that cutting edge 412 does not cut intothe vessel wall. An ultrasonic sensor 416 (see FIG. 17) is mounted inthe distal extremity of the tubular member 386 and is connected byconductors 393 (see FIG. 18) extending through the lumen 392 andconnected to a cable 418 which is connected to an ultrasonic powersupply 419 and a video monitor 421. By using the Doppler effect,ultrasonic energy can be utilized in connection with the transducer 416to ascertain the depth of cut being made by the flexible elongate member407 as it is being rotated.

As soon as a desired amount of plaque has been removed from the stenosis369 to provide the desired passage through the stenosis, rotation of thetubular member 386 is terminated after which the tubular member 386 canbe withdrawn followed by deflation of the second balloon 336 andwithdrawing it. Deflation of the first balloon 316 then occurs afterwhich it is withdrawn from the vessel 367. Thereafter, the guidingcatheter 363 can be removed and the incision closed as hereinbeforedescribed.

In order to ensure that restenosis will not take place, it may bedesirable to place a cylindrical stent 426 in the stenosis 369. Such astent 426 can be a self-expanding stent formed of a suitable materialsuch as a superelastic Nitinol and movable between unexpanded andexpanded conditions. Such a stent 426 can be placed by a suitablecatheter apparatus 431 of the type shown in FIG. 20. The stent 426 whichis cylindrical in form is pushed over the proximal extremity of thesecond elongate flexible tubular member 331 into the main or centrallumen 321 so that it is retained in the unexpanded position. It is thenpushed forwardly toward the distal extremity of the first flexibleelongate tubular member 316 by means of a flexible elongate tubularmember 436 having proximal and distal extremities 437 and 438 and havinga flow passage 439 extending from the proximal extremity 437 to thedistal extremity 438. The proximal extremity 437 is provided with aknurled collar 441 which is adapted to be engaged by the hand tofacilitate pushing of the flexible elongate tubular member 436 so thatits distal extremity is in engagement with the stent 426. Thus, whendesired the stent 426 may be discharged or dislodged from the distalextremity of the second tubular member 331 and pushed into the workingspace 376 created between the first balloon 319 and the second balloon336.

After the stent 426 has been discharged out of the end of the firstflexible elongate tubular member 316, the stent 426 will self expandtoward its expanded condition until it is in engagement with the wall ofthe vessel in the vicinity of the occlusion forming the stenosis 369 tofrictionally retain the stent in engagement with the vessel wall. Assoon as the stent 426 is in engagement with the vessel wall, the secondballoon 336 can be deflated as can the first balloon 319. The firstdeflated balloon 336 can then be withdrawn through the interior of thecylindrical stent 426. This can be followed by deflation of the firstballoon 319 and the removal of the flexible elongate tubular member 316with its first balloon 319 and the flexible tubular member 331 with itssecond balloon 336, along with the flexible elongate member 436 untilthe entire catheter assembly or apparatus 431 has been removed from theguiding catheter 363. Thereafter the guiding catheter 363 can be removedand the incision sutured as hereinbefore described.

In FIG. 21, there is shown another embodiment of an apparatus 451incorporating the present invention which is particularly adapted foruse treating a stenosis at or near a bifurcation appearing in anarterial vessel. The apparatus 451 is shown being used on a human being452 showing the principal arteries and pulmonary veins of the humanbody. Thus there as shown, the abdominal aorta 453 branches into thecommon iliac 454 which branches into the external iliac 456 and theinternal iliac 457. The external iliac branches into the deep femoralartery 458 and into the femoral artery 459. The abdominal aorta 453extending in the opposite direction passes through the aortic arch 461of the heart 462. The aortic arch 461 is connected to the common carotid466 which extends into a bifurcation 467 branching into the externalcarotid 468 and the internal carotid 469. Similar bifurcations appear inthe basilar artery which is an artery which is particularly inaccessiblefor surgical treatment.

As hereinafter explained, the apparatus 451 shown in FIGS. 21, 22 and 23consists of a proximal occlusion balloon catheter 476 which can beconsidered to be a first catheter. The catheter 476 is formed of aflexible elongate tubular member 477 having proximal and distalextremities 478 and 479. The tubular member 477 is formed of a suitablematerial such as plastic and can have a suitable size ranging from 5 to14 French and preferably 9 to 10 French. A balloon 481 is provided onthe distal extremity 479 and is formed of a suitable elastic material.It is generally cylindrical in form and has its proximal and distalextremities secured to the tubular member 477 by suitable means such asan adhesive (not shown). The tubular member 477 is provided with aplurality of lumens therein. One lumen 482 serves as a balloon inflationlumen and extends from the proximal extremity 478. It can have asuitable size such as 0.024″ and has port 483 in communication with theinterior of the balloon 481. A manifold 486 formed of a suitablematerial such as plastic is mounted on the proximal extremity 478. Atubular member 487 is mounted in the manifold 486 and is incommunication with the inflation lumen 482.

The tubular member 477 is also provided with a large lumen 491 having asuitable size as for example 0.045″ which is adapted to slidably receivetherein a therapeutic balloon catheter 492 and a perfusion ballooncatheter 493. It is also provided with another lumen 496 having asuitable size as for example 0.026″ which is adapted to receive aballoon-on-a-wire catheter 497. It is also provided with an aspirationlumen 501 having a suitable size as for example 0.025″ and an irrigationlumen 502 having a suitable size as for example 0.015″. There is alsoprovided another lumen 503 which can be used for other purposes.

The therapeutic balloon catheter 492 and the perfusion balloon catheter493 are constructed in a manner similar to the balloon cathetershereinbefore described. Thus the perfusion balloon catheter 493 isprovided with a flexible elongate tubular member 506 having proximal anddistal extremities 507 and 508. A balloon 509 formed of an elasticmaterial is secured to the distal extremity 508 by suitable means suchas an adhesive (not shown) and is adapted to be inflated through a port510 in communication with a balloon inflation lumen 511. The tubularmember 506 is also provided with a blood perfusion lumen 512 which iscentrally disposed therein. The proximal extremity 507 of the tubularmember 506 is connected to a Y adapter or fitting 513 of which thecentral arm 514 is in communication with the blood perfusion lumen 512and is provided with a Luer-type fitting 516. The side arm 517 of thefitting 513 is in communication with the balloon inflation lumen 511 andis provided with a Luer-type fitting 518 adapted to be connected to asource of pressure as hereinafter described.

The therapeutic balloon catheter 492 consists of a tubular member 521having a proximal and distal extremities 522 and 523. A balloon 524formed of a non-elastic material is secured to the distal extremity 523by suitable means such as an adhesive. A port (not shown) is incommunication with the interior of the balloon 524 and is incommunication with a balloon inflation lumen 526. A Luer-type fitting527 is mounted on the proximal extremity 522 and is in communicationwith the balloon inflation lumen 526. Another fitting 528 is mounted onthe proximal extremity 522 and is in communication with a largecentrally disposed lumen 529 which can receive the perfusion ballooncatheter 493 for slidable movement as hereinafter described.

The balloon-on-a-wire catheter 497 is slidably mounted in the lumen 496and consists of a guide wire 531 of a conventional construction having asuitable diameter as for example 0.018″ and having a proximal and distalextremities 532 and 533. A balloon 534 formed of a non-elastic materialis mounted on the distal extremity 533 and is secured thereto bysuitable means such as an adhesive (not shown). The proximal extremityof the balloon 534 is secured to the distal extremity of a tubularmember 536 formed of a suitable material such as plastic and which iscoaxially disposed on the guide wire 531. The tubular member 536 extendsthe length of the guide wire to the proximal extremity and is connectedto a Luer-type wye fitting 537 and is in communication with an annularlumen 538 disposed between the tubular member 536 and the exteriorsurface of the guide wire 531. The lumen 538 is in communication withthe interior of the balloon 534 for inflating and deflating the balloon534. The balloon-on-a-wire catheter 497 is adapted to be introducedthrough a fitting 541 carried by a tube 542 mounted in the manifold 486and in communication with the lumen 496 in the multi-lumen elongatetubular member 477.

A tube 546 is mounted in the manifold 486 and is in communication withthe large lumen 491 and is provided with a fitting 547 which is adaptedto receive the perfusion balloon catheter 493 and the therapeuticballoon catheter 492 as hereinafter described. Another tube 551 isprovided in the manifold 486 and is in communication with the aspirationlumen 501. It is provided with the fitting 552. Another tube fitting 553is mounted in the manifold 486 and is in communication with theirrigation lumen 502 and is provided with a fitting 554.

The various fittings for the catheter as hereinbefore described areadapted to be connected into a control console 571. The control console571 consists of a rectangular case 572 which is provided with a frontpanel 573.

A plurality of balloon inflation deflation devices 576 of a conventionaltype typically called endoflaters are mounted within the case 572 andhave control handles 577 extending through vertically disposed slots 578provided in the front panel. These endoflaters 576 are labeled as shownin FIG. 21 and are connected by tubing (not shown) through pressuregauges 581 mounted in the front panel 573 and are provided with needleindicators 582 to indicate the pressure being applied by the endoflaterto the tubing. The tubing is connected in such a manner so that theendoflater 576 and the associated pressure gauge 581 are connected to atube 586 which is provided with a mating fitting 587 adapted to matewith a fitting 488 so that it is in communication with the inflationlumen 482 of the proximal occlusion balloon catheter 476. In a similarmanner, the tubing 588 is provided with a fitting 589 which mates with afitting 518 of the balloon inflation lumen 511 of the perfusion ballooncatheter 493 for inflating balloon 509. Similarly, tube 591 with itsmating fitting 592 is adapted to mate with the fitting 537 for inflatingthe balloon 534. Similarly, the tube 593 with its fitting 594 mates withthe fitting 527 in communication with the balloon inflation lumen 526for inflating the balloon 524 of the therapeutic catheter 492. Anothertube 596 which is provided with its fitting 597 mates with the fitting552 that is in communication with the aspiration lumen 501. The tube 596is in communication with the inlet of a blood pump 601 of a suitabletype as for example a roller pump well known to those skilled in the artwhich is mounted within the case 572 and which is connected to a sourceof electrical power through electrical plug 602 connected into the case572. The roller pump 601 is provided with an on/off switch 603 mountedon the front panel 573. After it passes through the pump 601, blood issupplied to a blood filter 606 of a conventional type and then issupplied through a tube 611 having a fitting 612 adapted to mate withthe fitting 516 of the perfusion balloon catheter which is incommunication with the perfusion lumen 512.

A three-way valve 616 is associated with each of the endoflaters 576 andhas a control knob 617 extending through the front panel 573 and isadaptable to be moved between three positions with a center off positionand an aspiration position in a counter-clockwise direction and apressurized position in a clockwise position as viewed in FIG. 24.

Operation and use of the apparatus 451 may now be briefly described asfollows. Let it be assumed that it is desired to treat a stenosisoccurring in a bifurcation in a carotid artery as depicted by theillustrations shown in FIGS. 25A through 25D. As shown in theillustration in FIG. 25A, let it be assumed that a stenosis is presentadjacent the bifurcation 467 and in the external carotid 468 and that itis desired to treat this stenosis in accordance with the apparatus 451of the present invention in performing the method of the presentinvention. The proximal occlusion balloon catheter 476 is loaded withthe therapeutic balloon catheter 492 slidably mounted over the perfusionballoon catheter 493 and both are slidably mounted in the main lumen491. The balloon-on-a-wire catheter 497 is slidably mounted in thelumen. While the patient is being prepared for the procedure, all of thelumens in the catheters of the apparatus are flushed with saline toremove all air from the lumens. They are then connected to the controlconsole 571 in the manner hereinbefore described and as shown in FIG.21. An incision 626 (see FIG. 21A) is made in the femoral artery in theleft leg of the patient and a guiding catheter (not shown) similar tothe type utilized in angioplasty is introduced through the femoralartery 459. This guiding catheter is advanced until it is near the aortaarch 461. Thereafter, the first or proximal occlusion balloon catheter476 has its distal extremity 479 introduced into the guiding catheterand advanced in the guiding catheter. It is advanced so that its distalextremity 479 enters the common carotid and is near the bifurcation 467.The balloon 481 is inflated by operating the control handle 577associated with the proximal occlusion balloon 481 as shown in FIG. 25Ato create the desired pressure within and to inflate the elastic balloon481 so that it occludes the common carotid just proximal of the stenosis624. As soon as this occurs, the roller pump 601 is turned on byoperating the on/off switch 603 to create a negative pressure on thedistal side of the balloon 481 to cause blood to flow in a reversedirection as shown by arrows 627 to thereby change the directional flowof blood from the internal and external carotids away from the brainrather than to the brain. The blood travels into the aspiration lumen501 as indicated by the arrows 627 and into the tube 551 throughfittings 552 and 597 and tube 596 to the roller pump 603. The bloodafter passing through the roller pump 603 passes through a blood filter606 and then passes into the tube 611 and the fitting 612 and connectedto the fitting 589 of the perfusion catheter 493. Alternatively, thefitting 612 can be which is connected to another fitting 631 mounted ona tube 632 introduced into the venous side of the circulatory system ofthe patient's body, as for example into the vein in the right leg of thepatient 452 as shown in FIG. 21. Any debris or emboli in the aspiratedblood being pumped will be filtered out by the blood filter 606.

As soon as or during the time this retrograde circulation of blood isestablished through the roller pump 601, the perfusion balloon catheter493 extending proximally from the fitting 547 is advanced into theinternal carotid 469 past the stenosis 621 at the bifurcation 467. Ifnecessary, a guide wire can be utilized which can be introduced throughthe perfusion lumen 512 to aide in advancing the perfusion ballooncatheter 493 into the internal carotid 469. Any emboli or debrisdislodged from the stenosis 621 by crossing the same either by the guidewire or by the distal extremity of the catheter 493 will be picked up bythe retrograde flow of blood which is being aspirated through theproximal occlusion balloon catheter 476 to thereby prevent any emboli ordebris from entering the brain of the patient. The elastic perfusionballoon 509 is then inflated as shown in FIG. 25B using the appropriateendoflater to inflate the balloon to the desired pressure while watchingthe associated pressure gauge. As soon as occlusion occurs, perfusion ofblood can be started as hereinafter described.

Prior to or after the balloon 509 of perfusion catheter 493 has beeninflated, the balloon-on-a-wire catheter 497 extending proximally of thefitting 541 is advanced into the external carotid 469 as shown in FIG.25C. The balloon 534 is then expanded by use of the appropriateendoflater to supply an inflating medium through the fitting 537 toocclude the external carotid 469. As soon as occlusion has beenaccomplished in both the external and internal carotids, retrograde flowof blood is terminated by shutting off the roller pump 601. It should beappreciated that if desired, automatic controls can be provided wherebywhen a certain pressure is reached in each of the balloons 509 and 534the roller pump would automatically be shut off to stop retrograde flow.By this procedure, it can be seen that the lesion of stenosis 621 hasbeen bracketed by the balloons 481, 509 and 534. Prior to thatoccurring, retrograde flow of blood is established to prevent any embolior debris from moving towards the brain.

As soon as retrograde flow of blood has been terminated, perfusion ofblood is started. This can be accomplished by connecting a cannula (notshown) to the fitting 516 of the perfusion catheter 506 and to obtain asupply of blood from the femoral artery in the other leg of the patient.Alternatively, an outside blood supply can be used. Thus fresh bloodwill be supplied from the femoral artery of the patient directly intothe perfusion balloon so that it is discharged distally of the perfusionballoon 509 as shown by the arrows 628 to continue to supply blood tothe carotid artery. It has been found that it is unnecessary to a supplyperfusion of blood to the external carotid artery because there issufficient auxiliary circulation in that carotid artery during the timethe procedure is taking place.

In the event there is inadequate pressure on the arterial blood beingperfused to overcome the resistance in the lumen 469, the roller pump601 can be utilized by merely operating the same in a reverse directionand connecting it between the cannula and the perfusion catheter.

After the lesion or stenosis 621 has been bracketed as hereinbeforedescribed and a working space 636 formed adjacent the stenosis or lesion621, a therapeutic procedure can be employed. By way of example this canconsist of advancing the therapeutic balloon catheter 492 over andaxially of the perfusion catheter 493 to bring its balloon 524 intoregistration with the stenosis 621 as shown in FIG. 25D. Thereafter, theballoon 524 can be inflated by use of the appropriate endoflater ashereinbefore described to cause the inelastic balloon to be pressurizedto a pressure of 10 to 15 atmospheres to compress the stenosis 621.Prior to or during this procedure it may be desirable to introduce asaline or heparin solution or a radiopaque contrast liquid into theworking space 636. This can be accomplished by introducing this liquidthrough the injection lumen 502. If desired, this can be accomplishedprior to terminating the aspiration procedure hereinbefore described.Also it should be appreciated that if desired a small endoscope can beinserted through one of the lumens to view the area within the workingspace. Alternatively, if desired an ultrasonic probe can be utilized toview the area in which the lesion is disposed.

As hereinbefore described with a previous embodiment, in place of thetherapeutic balloon catheter, other types of catheters can be utilizedas for example one incorporating an atherectomy device of the typehereinbefore described to facilitate removal of the stenosis. It isreadily apparent that during these procedures if it is necessary tosupply a saline solution or a heparinized solution into the workingspace that the working space can also be continued to be aspirated toremove any debris or emboli which occur during the procedure.

Let it be assumed that the desired therapeutic actions have beenundertaken and that the stenosis 621 has been reduced and substantiallyeliminated so that there is adequate flow through the internal carotid.If it can be seen that there also is a stenosis in the external carotid,the balloon-on-a-wire catheter 497 and the perfusion catheter 493 can bewithdrawn and moved so that they enter the opposite carotid to permittherapeutic treatment of a stenosis occurring in the other carotid.

When all the desired therapeutic procedures have been accomplished, thesupply of saline or contrast solution can be terminated and thetherapeutic balloon 524 deflated. The balloon 534 of theballoon-on-a-wire catheter can be deflated as well as the perfusionballoon 509. Perfusion of blood through the perfusion catheter can beterminated. The perfusion balloon catheter 493 and the balloon-on-a-wirecatheter 497 can be retracted into the main multi-lumen tubular member477 of the proximal occlusion balloon catheter after which the perfusionballoon catheter can be withdrawn carrying with it the other cathetersdisposed therein. Thereafter, the guiding catheter can be removed and asuture applied to the incision made to gain access to the femoralartery.

It is readily apparent that similar procedures can be carried out withrespect to other vessels in the body, such as saphenous vein grafts inthe heart, and particularly with respect to vessels in the brain whereit is difficult if not impossible to employ surgical procedures as forexample with respect to the basilar arteries in which bifurcationsappear.

As also herein before explained, the catheter apparatus of the presentinvention can be utilized for deploying stents. Where that is desirablethe apparatus of the present invention, perfusion can be accomplishedduring employment of the stent.

From the foregoing it can be seen that an apparatus and method has beenprovided for treating occluded vessels and particularly for treatingcarotid arteries. The apparatus and method of the present invention isparticularly advantageous for the carotid arteries because it permitsaccess to portions of the carotid arteries which are not accessible bysurgery.

The catheter apparatus assembly and method of the present invention arealso particularly useful for treating other occluded vessels butparticularly the carotid arteries because it makes possible the removalof plaque without endangering the patient. An operating or working spaceis provided while shunting blood around the working space so that thereis continued blood flow in the vessel to support the functions which arenormally supported by the vessel. As also pointed out above, theapparatus and method of the present invention are particularly useful inconnection with vessels having bifurcations therein and in which thestenosis occurs at or near the bifurcation. From the foregoing it can beseen with the apparatus and method of the present invention, retrogradeflow of blood is accomplished during deployment of the device to preventundesired travel of emboli. Occlusion of the vessels is provided toobtain a working space by bracketing the working space with balloonswhile at the same time maintaining perfusion of blood making it possibleto utilize a substantial period of time for undertaking therapeuticprocedures with respect to the bracketed stenosis.

In connection with the present apparatus and method for treatingoccluded vessels, it has been found that it is possible to utilize theapparatus and method without perfusion and other procedures involvingthe carotid arteries and saphenous vein grafts for periods of timeextending over five minutes and greater which has made it possible tosimplify the apparatus and the method utilized in conjunction therewith.

With respect to an apparatus or assembly which does not require the useof perfusion, a main catheter 651 utilized as a part of the apparatus isshown in FIGS. 26, 27, 28 and 29 consists of a flexible elongate tubularmember 652 formed of a suitable material such as plastic of the typehereinbefore described and which has proximal and distal extremities 653and 654. The tubular flexible elongate tubular member 652 can be ofvarious sizes as for example for a saphenous vein graft catheter it canbe 8 to 9.5 French in balloon profile with a length ranging from 80 cmto 120 cm. The flexible elongate tubular member 652 can be formed of asuitable material such as PEBAX®, Nylon, HYTREL®, polyurethane orpolyethylene. A flexible braid 656 (see FIGS. 27, 28 and 29) formed of asuitable material such as stainless steel is embedded within the wall ofthe flexible elongate tubular member 652 as shown and extends from theproximal extremity 653 to the distal extremity 654. The braid 656 can beformed of a suitable stainless steel such as a wire or ribbon having athickness of 0.001″. The braid 656 provides additional torquability andalso inhibits the kinking of the flexible elongate tubular member 652when it must extend over a tight radius. The flexible elongate tubularmember 652 is provided with a large central lumen 657 having a suitablediameter such as 0.065 or greater” extending from the proximal extremityto the distal extremity.

If it is desired to provide a flexible elongate member 652 which has agreater flexibility at the distal extremity, a different material can beused in the distal extremity 654. For example, the distalmost 5-15centimeters can be formed of a material such as PEBAX® having a Shore Dhardness of 35-50 with the remainder of the flexible elongate member 652having a Shore D hardness of 65-75.

A supplemental flexible elongate tubular member 661 is provided whichhas incorporated therein a balloon inflation lumen 662. The supplementalflexible elongate tubular member 661 can be of a suitable size as forexample an I.D. of 0.014″ and an O.D. of 0.018″ and formed of a suitablematerial such as a polyimide. The supplemental flexible elongate tubularmember has a length which is almost as long as the flexible elongatetubular member 652 and overlies the outside wall of the flexibleelongate tubular member 652 and extends from the proximal extremity tonear the distal extremity as shown in FIGS. 26 and 29. A tube 663 of asuitable material such as PEBAX® extends over the length of thepolyimide tubing 661 and is secured to the flexible elongate tubularmember 652 by a shrink tube 666 extending from the proximal extremity653 to the distal extremity 654, after which the shrink tube 663 issubjected to heat. The shrink tube 666 is then subjected to a hot meltprocess of a temperature around 350° F. for a period of time until thePEBAX® tube 663 melts, after which the shrink tubing 666 can be strippedoff so that there remains a relatively uniform mass formed of PEBAX®that surrounds the braid 657 and the polyimide tube 661 which forms thesupplemental flexible elongate tubular member 661. The polyimide tubewhich forms the supplemental flexible elongate tubular member 661 thusprovides an inflation lumen 667 extending from the proximal extremityand to the distal extremity and opens through an opening 668 into theinterior of an occlusion balloon 669 which is bonded to and coaxiallymounted on the distal extremity of the flexible elongate member 652 inthe manner shown in FIG. 29. The polyimide tubing is provided to givethe balloon inflation lumen shaft 361 greater strength than that whichis provided by the PEBAX® itself

As can be seen from FIG. 29, the supplemental flexible elongate tubularmember 661 is terminated short of the distal most extremity of theflexible elongate tubular member 652 by approximately 1 cm. Theocclusion balloon 669 is formed of various compliant or non-compliantmaterials. Suitable compliant materials include elastomers such asC-FLEX® latex, silicones and polyurethanes. Suitable non-compliantmaterials would be polyethylene, PET and Nylon. A composite material canalso be used such as a combination of PET and an elastomer. Theocclusion balloon 669 should have a strength so that it can readilyaccommodate any pressure of one atmosphere and as high as fouratmospheres, or approximately 60 psi. The occlusion balloon 669 iscylindrical and is provided with proximal and distal extremities 671 and672 which are secured by a suitable medical grade adhesive.Alternatively, fuse bonding may be used. Thus a seal 673 formed of thisadhesive bonds the proximal extremity 671 of the occlusion balloon 669over the outer surface of the distal extremity of the flexible elongatetubular member 652 and the supplemental flexible elongate tubular member661. Similarly, a seal 674 bonds the distal extremity 672 to the distalextremity of the flexible elongate tubular member 652 to provide anair-tight space within the balloon accessible through the opening 668. Asoft cylindrical tip 676 formed of suitable material such as PEBAX® isbonded to the distal extremity of the flexible elongate tubular member652 and is provided with a rounded surface 677 which extends forwardlyand has a passage 678 therein in communication with the lumen 657 andthe flexible elongate tubular member 652. A cylindrical radiopaquemarker 681 formed of a suitable material such as platinum,platinum-iridium or gold is mounted on the distal extremity of theflexible elongate tubular member 652 in a position so it issubstantially equidistant of the ends of the occlusion balloon 669.

A main adapter or fitting 686 formed of a suitable material such asplastic is mounted on the proximal extremity 653 of the flexibleelongate tubular member 652. It is provided with a first Luer fitting687 which provides a balloon inflation port 688 in communication withthe balloon inflation lumen 662. It is also provided with another Luerfitting 689 which is provided with an aspiration port 691 incommunication with the main central lumen 657. The main adapter 686 isalso provided with a Tuohy-Borst fitting 692 which is in communicationwith the central lumen 657. The Tuohy-Borst fitting 692 is adapted toreceive therapeutic devices, as for example a balloon-on-a-wire deviceas hereinafter described and is adapted to form a liquid-tight sealtherewith by an o-ring 693.

A balloon-on-a-wire device 701 incorporating the present invention isshown in FIGS. 30 and 31. The device 701 consists of a guide wire 702formed of a suitable material such as stainless steel and having asuitable diameter as for example ranging from 0.010″ to 0.032″ butpreferably a diameter ranging from 0.014″ to 0.018″. It is preferablethat the guide wire 702 be formed of a nickel titanium alloy typicallycalled Nitinol which has the advantage that it is more flexible and hasgreater kink resistance characteristics than another suitable materialsuch as stainless steel.

It has a suitable length as for example 150 cm. The guide wire 702 isprovided with proximal and distal extremities 703 and 704 and isprovided with a central lumen 706 extending from the proximal extremityto the distal extremity. The lumen can be of a suitable size as forexample 0.010″ I.D. for an 0.014″ O.D. guide wire.

An occlusion balloon 711 is coaxially mounted on the distal extremity704 of the guide wire 702. The occlusion balloon 711 is preferablyformed of the same material as the occlusion balloon 669 on the maincatheter 651. The occlusion balloon 711 has proximal and distalextremities 712 and 713. A tube 716 formed of a suitable material suchas a polyimide is disposed within the occlusion balloon 711 and has abore 717 extending therethrough which is sized so that it is slightlylarger than the outside diameter of the guide wire 702 so that itsproximal extremity can be slipped over the distal extremity 704 of theguide wire 702 and then bonded thereto by suitable means such as anadhesive 718. A plurality of circumferentially spaced apart radiallyextending inflation holes 719 are provided in the proximal extremity ofthe tube 716 and are in alignment with similarly spaced holes 721provided in the distal extremity 704 of the guide wire 702 so that theyare in communication with the central lumen 706 of the guide wire 702.The inflation holes 719 as shown are in communication with the interiorof the occlusion balloon 711 so that fluid passing from the passage 706can be utilized for inflating the occlusion balloon 711.

A solid core wire 723 formed of a suitable material such as stainlesssteel is provided with a proximal tapered extremity 724. The core wire723 is sized so it is adapted to fit within the lumen 706 of the guidewire 702 and is secured therein by suitable means such as an adhesive726 or alternatively a weld. The core wire 723 has a tapered portion 723a which commences at the proximal extremity 724 and which is tapered sothat the cross-sectional diameter progressively decreases to the distalextremity of the occlusion balloon 711. The core wire 723 is alsoprovided with additional portions 723 b and 723 c which can be ofsubstantially constant diameter as for example 0.003″. The portion 723is folded over with respect to the portion 723 b so that the portions723 b and 723 c lie in a plane to facilitate shaping of the distalextremity of the guide wire 702 during use of the same. The core wire723 is provided with a distal extremity 727 in which a bend 728 isformed between the two portions 723 b and 723 c. The bend 728 is securedwithin a hemispherical solder bump or protrusion 729 which is carried bythe distal extremity of a coil 731 formed of a suitable radiopaquematerial such as platinum or a platinum alloy. The platinum coil 731 canhave a suitable outside diameter as for example 0.014″ corresponding tothe diameter of the guide wire 702 and can have a suitable lengthranging from 1 to 3 cm. The proximal extremity of the coil 731 issecured to the distal extremity of the polyimide tube 716 by suitablemeans such as an adhesive 732 which can be the same adhesive or adifferent adhesive 733 utilized for securing the distal extremity 713 ofthe balloon to the polyimide tube 716 to form a fluid-tight seal betweenthe distal extremity of the occlusion balloon 711 and the distalextremity of the polyimide 716. From this construction it can be seenthat the portions 723 b and 723 c of the core wire 723 in addition toserving as a shaping ribbon are also utilized as a safety ribbon toensure that the tip 728 and the spring 731 cannot be separated from theguide wire 702. The proximal extremity 712 of the balloon 711 is alsosecured to the proximal extremity of the polyimide tube 716 and also tothe distal extremity 704 of the guide wire 702 to form a fluid-tightseal with respect to the occlusion balloon 711 so that the occlusionballoon 711 can be inflated and deflated through the inflation holes 719and 721.

Alternative constructions for the distal extremity of the core wire 723are shown in FIGS. 33 and 34. In FIG. 23 it can be seen that theportions 723 b and 723 c have been twisted to in effect provide atwisted pair serving as a safety ribbon and as a shaping ribbon. In theembodiment shown in FIG. 34, the core wire 736 is provided with atapered portion 736 a which is the same as the tapered portions of 723 ahereinbefore described. However, the core wire 736 has been providedwith a distal portion 736 b which has been flattened to a suitablethickness as for example a width of 0.006″ and a thickness of 0.003″ andthen twisted to form a helix as shown in which the distal extremity isembedded within the solder 729. Such a helix 736 can serve as a safetyribbon and also can be shaped to some extent.

A removable inflation fitting 741 or valve attachment 741 is mounted onthe proximal extremity of the guide wire 702 and forms a part of theballoon-on-a-wire device 701. The fitting or attachment 741 is formed ofa suitable material such as a polycarbonate and is provided with acentral bore 742. The attachment or fitting is slid externally over theproximal extremity 703 of the guide wire 702. Means is provided forforming a fluid-tight seal between the proximal extremity 703 of theguide wire 702 and a body 743 of the fitting 741 and consists of ano-ring 746 (see FIG. 35) seated in a well 747. A thumb screw 748 isthreadedly mounted on the body 743 and is provided with an inwardlyextending circular protrusion 749 that is adapted to engage the o-ring746 and to compress the same to form a fluid-tight seal when theprotrusion 749 is moved inwardly toward the o-ring 746 as the thumbscrew 748 is rotated in a clockwise direction. The o-ring 746decompresses or springs back when released upon rotation of the thumbscrew 748 in a counterclockwise direction so that the fitting 741 can beremoved from the proximal extremity 703 of the guide wire 702. The body743 also includes a Luer fitting 751 which provides an inflation port752 that is in communication with the bore 742 in the body 743 and whichis also in communication with the open proximal extremity of the guidewire 702 and the lumen 706 therein.

Means is provided for plugging the bore 706 when the removableattachment or fitting 741 is removed and consists of a plug mandrel 756formed of a suitable material such as 0.014″ stainless steel solid rod.It is necessary that this rod have a diameter which is greater than thediameter of the lumen 706 and the guide wire 702. The plug mandrel 756is provided with a progressive portion 756 a that tapers down from as,for example from 0.014″ to a suitable diameter as for example 0.008″ toa cylindrical portion 756 b.

Means is provided for forming a fluid-tight seal between the plugmandrel 756 which forms a plug mandrel and the body 743 of theattachment or fitting 741 and consists of an o-ring 761 providingsuitable sealing means seated within a well 762 provided in the body743. A thumb screw 763 threadedly engages the body 743 and is providedwith a cylindrical protrusion 764 which engages the o-ring andcompresses it to form a fluid-tight seal with respect to the plugmandrel 756 by rotation in a clockwise direction of the thumb screw 763.The plug mandrel 756 can be released by a counterclockwise rotation ofthe thumb screw 763 permitting decompression of the o-ring 761.

An irrigation catheter 766 incorporating the present invention is shownin FIG. 36 and consists of a flexible elongate tube 767 formed of asuitable material such as polyethylene, PEBAX®, HYTREL® or Teflon havinga suitable size as for example an outside diameter of 0.066″ and aninside diameter of 0.058″ and having a length of approximately 150 cm. Alumen 768 is provided therein and extends from the proximal extremity tothe distal extremity and is in communication with an adapter 769provided on the proximal extremity of the tube 767. The adapter 769 isprovided with a body 770 formed of a suitable material such as plasticand is provided with a bore 771 extending therethrough. The adapter 769is provided with a side arm 772 which carries a conventional Luer-typeconnection and provides an irrigation port 773 in communication with thebore 771. A thumb screw 774 threadedly mounted on the body 770 carries acylindrical protrusion 776 adapted to compress an o-ring 777 carried bythe body 770 into engagement with a therapeutic catheter of the typehereinafter described. A radiopaque tip marker 778 of a suitable type,as for example one formed as a platinum-iridium band 778 is provided onthe distal extremity of the flexible elongate element 767 to facilitatepositioning of the irrigation catheter as hereinafter described.

Operation of the apparatus shown in FIGS. 26 through 36 in performingthe method of the present invention for treating occluded vessels maynow be briefly described as follows utilizing the cartoons which areshown in FIGS. 37-43. Let it be assumed that it is desired to treat avessel 781 in the human body as for example a saphenous vein grafthaving at least a partial occlusion or stenosis 782 which is formed byplaque in the vessel. The main catheter 651 is introduced into the bodythrough a conventional procedure such as for example by making anincision into the femoral artery in a leg of the patient.

Thereafter the main catheter 651 can be introduced into the femoralartery by use of a large conventional guiding catheter because the maincatheter 651 is of a relatively large size, as for example 8 to 9.5French. In order to eliminate the need for such a large guidingcatheter, a smaller conventional guiding catheter 786 of the type shownin FIG. 37 can be utilized which can be introduced through the maincatheter 651. Utilizing such a catheter, the main catheter 651 can beinserted independently through a conventional sheath (not shown) in thefemoral artery and thereafter the guiding catheter 786 is introducedthrough the main catheter 651 so that its distal extremity 789 is in thevessel. Alternatively, the guiding catheter 786 can be deployed into themain catheter 651 and the guiding catheter 786 introduced at the sametime into the femoral artery.

The guiding catheter 786 is conventional and thus will not be describedin detail. It consists of a flexible elongate tubular member 787 (seeFIG. 37) formed of a suitable material such as plastic having proximaland distal extremities 788 and 789. The distal extremity 789 is providedwith a preformed bend as shown. An adapter 792 is mounted on theproximal extremity 788 and consists of a body 793 in the form a wye inwhich the central leg 794 is provided with a flow passage (not shown)therein in communication with the central lumen (not shown) extendingfrom the proximal extremity 788 to the distal extremity 789 of theflexible elongate tubular member 787. The body 793 is provided with aside leg 796 which also is in communication with a lumen (not shown)extending from the proximal extremity 788 to the distal extremity 789. Aknob 797 carrying an o-ring (not shown) secures the adapter 792 to theproximal extremity 788 with a fluid-tight seal. Another knob 798 isprovided which is carried by the central leg 794 of the body 793 and isprovided with an o-ring (not shown) which can be moved to close the flowpassage in the central leg 794, or alternatively it can be opened toreceive a guide wire which can be utilized for advancing the guidecatheter 786 if that be necessary and then forming a fluid-tight sealwith respect to the guide wire.

Assuming that the guiding catheter 786 has been inserted into the maincatheter 651 before insertion of the main catheter 651 into the femoralartery, both catheters can be inserted in unison while advancing thedistal extremity of the guide catheter 786 so that it precedes thedistal extremity of the main catheter 651 and serves to guide the maincatheter 651 into the vessel of interest, as for example the vessel 781having the stenosis 782 therein. The main catheter 651 is then advancedso that its distal extremity is at the proximal side of the stenosis782. By way of example, the main catheter 651 can be advanced throughthe aortic arch of the heart and thence into a saphenous vein graft sothat the occlusion balloon 669 on its distal extremity is positionedproximal of the stenosis 782. As soon as this has been accomplished, theguiding catheter 786 can be removed.

As soon as the distal extremity of the main catheter 651 has beendeployed so that it is just proximal of the stenosis 782 to be treated,an assembly shown in FIG. 38 is introduced into the main catheter 651.This assembly can be provided by preloading the irrigation catheter 766onto the therapeutic catheter 801 by inserting the distal tip of thetherapeutic catheter 801 through the fitting 769 of the irrigationcatheter 766 and advancing the therapeutic catheter 801 until itstherapeutic balloon 809 exits from the irrigation catheter 766. Theballoon-on-a-wire catheter 701 also is preloaded by removing the valveattachment 741 and then inserting the proximal end 703 into the guidewire lumen at the distal tip of the therapeutic catheter 801 and thenadvanced proximally until the proximal end protrudes out of the proximalend of the therapeutic catheter. The valve attachment 741 is thenreattached to the proximal end 703. The preassembled irrigation catheter766, the therapeutic catheter 801 and the balloon-on-a-wire catheter 701are then introduced in unison as an assembly into the main catheter 651.The balloon-on-a-wire device 701 is then advanced until the distalextremity is near the distal extremity of the main catheter 651 butbefore the distal extremity has been advanced through the stenosis 782.

Let it be assumed that it is now desired to inflate the occlusionballoon 669 carried by the main catheter 651. This can be accomplishedin a suitable manner such as with an inflation-deflation devicerepresented schematically by a syringe 802 secured to the fitting 687(see FIG. 38) and supplying a balloon inflation fluid through theballoon inflation lumen 662 to inflate the occlusion balloon 669 to anocclusion pressure ranging from 1 to 3.9 atmospheres and preferablyapproximately one to two atmospheres to engage the side wall forming thevessel 781 to occlude the vessel 781 and to prevent further blood flowthrough the vessel and to thereby provide a working space 803 distal ofthe occlusion balloon 669. As soon as the occlusion balloon 669 has beeninflated, the balloon-on-a-wire device 701 can be advanced across thelesion or stenosis 782 until the deflated occlusion balloon 711 carriedthereby is distal of the stenosis 782. It is safe to cross the stenosis782 because the flow of blood through the stenosis 782 has been occludedby the occlusion balloon 669. Thus if any of the plaque forming thestenosis is dislodged by the occlusion balloon 711 on theballoon-on-a-wire device 701 as the occlusion balloon 711 is crossingthe stenosis 782, the plaque particles or emboli 804 will not be carriedoff by blood. The positive pressure of blood in secondary collaterals orvasculature will prevent emboli from traveling downstream into thesecondary vasculature. If desired, aspiration can be supplied to theworking space 803 encompassing the stenosis 782 by placing a suitablevacuum connected to the fitting 689 of the main catheter.

The occlusion balloon 711 can then be readily inflated by use of asyringe 805 secured to the fitting 751 of the removable valve fitting orattachment 741 of the balloon-on-a-wire device 701 proximal of thefitting 686 and accessible outside the body of the patient. Theocclusion balloon 711 is inflated (see FIG. 39) to at leastapproximately one to two atmospheres to bracket the stenosis and todetermine the size of the working space 803 to provide a chamber. Itshould be appreciated that the size of this working space or chamber 803can be adjusted by changing the position of the occlusion balloon 711 inthe vessel 781. If desired, this can be accomplished while the occlusionballoon 711 is inflated.

Now let it be assumed that the occlusion balloon 711 has been inflatedwith the appropriate working space 803 and that it is desired tointroduce a therapeutic balloon catheter 801 into the working space 803to treat the stenosis 782. If the therapeutic catheter 801 is not in themain catheter 651 as hereinbefore described, this can be readilyaccomplished in the present invention by inserting a plug mandrel 756into the open end of the lumen 706 of the guide wire 702. After the plugmandrel 756 has been inserted, the syringe 805 can be removed afterwhich the thumb screws 748 and 763 can be loosened to permit the o-ringstherein to become decompressed and to release the guide wire 702 and theplug mandrel 756 to permit the fitting or valve attachment 741 to beslipped off to provide a proximal end on the guide wire 702 which isfree of obstructions. During removal of the valve attachment or fitting741, the occlusion balloon 711 remains inflated and continues to bedisposed distally of the stenosis 782. The occlusion balloon 669 alsoremains inflated because the syringe 802 remains attached to the fitting686 and is disposed proximal of the stenosis 782.

The conventional therapeutic catheter 801 then can be delivered over theguide wire 702 if it is not already present. The therapeutic catheter801 is provided with a flexible elongate tubular member 806 havingproximal and distal extremities 807 and 808 with a central flow passage(not shown) extending between the same. A therapeutic balloon 809 on itsdistal extremity is adapted to be inflated to therapeutic pressuresranging from 4-20 atmospheres through a balloon inflation lumen (notshown) carried by the flexible elongate tubular member 806 through anadapter 811 mounted on the proximal extremity 807. The therapeuticballoon 809 can be considered to be means for performing work carried bythe distal extremity 808 of the flexible elongate tubular member 806.The adapter 811 can be removable of the type hereinbefore described oralternatively can be permanently attached thereto. Assuming that it is aremovable adapter, the removable adapter 811 is provided with knobs 812and 813 carrying o-rings (not shown) adapted to establish fluid-tightseals with the flexible elongate member 806 and the plug mandrel 756,respectively. It is also provided with an inflation port 816 similar tothose hereinbefore described which is in communication with theinflation lumen (not shown) provided in the flexible elongate tubularmember 806 for inflating the therapeutic balloon 809.

After the balloon catheter 801 has been positioned by the use ofradiopaque markers (not shown) conventionally employed in such devices,the therapeutic balloon 809 is disposed so that it is in generalalignment with the stenosis 782 as shown in FIG. 39. The therapeuticballoon 809 is then inflated in a conventional manner to perform work byuse of an inflation-deflation device schematically represented by thesyringe 817 attached to the inflation port 816 to the desired pressureto compress the plaque forming the stenosis 782 as shown in FIG. 40 toincrease the size of the opening through the stenosis 782 in the vessel781.

Let it be assumed that during the compression of the plaque forming thestenosis 782, additional emboli 804 are formed as shown in FIG. 41 bypieces of plaque becoming dislodged from the plaque 782 within thevessel 781. Let it also be assumed that it is desired to remove theseemboli before deflation of the occlusion balloons 669 and 711 disposedproximally and distally of the stenosis 782. To accomplish this, thetherapeutic balloon 809 is deflated by use of the syringe 817. As soonas this has been accomplished, a saline solution can be introducedthrough the irrigation catheter 766 by connecting a tube 819 carryingthe saline solution from a suitable source as for example a free orpressurized saline bag (not shown) and delivered through the irrigationport or side arm 772 where it is carried through the large central lumenof the irrigation catheter 766 so that the saline solution is dischargedinto the working space 803 disposed between the occlusion balloons 711and 669 as shown in FIG. 41. At the same time suitable aspiration meansis connected to the aspiration port 689 of the adapter 686 and as showncan consist of a hand operated bulb 821 which has a one way check valve822 therein connected to the fitting 689.

The bulb 821 is provided with another one-way check valve 823 which isconnected to a flexible collection bag 824. The bulb 821 makes itpossible to generate a vacuum corresponding approximately to 3-30″ ofmercury. Thus, by compressing the bulb 821 by hand, it is possible tocreate suction within the chamber or space 803 formed in the vesselbetween the occlusion balloons 669 and 711 each time the bulb 821 iscompressed and released. Alternatively, the aspiration can beaccomplished by use of a syringe in place of the bulb 821 and thecollection bag 824. Saline liquid supplied through the irrigationcatheter 766 carrying the emboli 818 is aspirated through the centrallumen 657 of the main catheter 651. The aspirated liquid in each cycleof operation created by pressing the bulb 821 is delivered to thecollection bag 824. With such a procedure it has been found that it ispossible to aspirate emboli as large as 600 μm. Such removal can beassured by observing when clear liquid exits outside the body from theaspiration port 691. A chamber having a length ranging from 3 cm to 15cm can be totally cleared of emboli within a short period of timeranging from 5 to 30 seconds. Alternatively, irrigation can beaccomplished by removing the therapeutic catheter 801 after deflatingthe therapeutic balloon 809. The irrigation catheter can be advancedover the balloon-on-a-wire device 701 until the distal tip is justproximal of the occlusion balloon 711 as shown in FIG. 42 to provide agreater flow of saline and faster aspiration.

After all of the emboli 804 have been removed, introduction of salinethrough the tube 819 is halted. It should be appreciated that the portsfor irrigation and aspiration can be reversed in function if desired.Thereafter, the occlusion balloon 711 is deflated by removing the plug756 and utilizing a syringe 805, after which the occlusion balloon 669is deflated permitting blood flow to be reestablished in the vessel 781.Alternatively, the occlusion balloon 669 can be first deflated andaspiration commenced at that time, permitting emboli trapped distally ofthe occlusion balloon 669 by blood flowing from the proximal side of theocclusion balloon 669 to be aspirated through the central lumen 657. Inorder to prevent excessive expansion of the vessel 781 being treated,the pressure of the irrigation liquid is typically maintained under 30psi. This pressure preferably should be below the occlusion balloonpressure.

If it is desired to deliver a stent to the site of the stenosis formedby the plaque 782, this can be readily accomplished during the sameprocedure. Typically it is desirable to permit the blood to flownormally for a period of several minutes after which the occlusionballoon 669 can be reinflated by the syringe 805 and the occlusionballoon 711 can be reinflated by inserting the removable valveattachment 741 if it has been removed of the balloon-on-a-wire device701 and utilizing the syringe 803 to reinflate the occlusion balloon711. The plug mandrel 756 can be inserted to keep the occlusion balloon711 inflated after which the valve attachment 741 can be removed.

A conventional stent delivery catheter 826 carrying a stent 827 on itsflexible shaft 828 is introduced over the balloon-on-a-wire device 701and delivered to the site of the dilated stenosis 782 (see FIG. 43). Thestent 827 can be of the self-expanding type or of the type which can beexpanded by a balloon (not shown) carried by the catheter 826 byconnecting a syringe 829 to an adapter 830 of the type hereinbeforedescribed of the stent delivery catheter 826. After the stent 827 hasbeen deployed in the dilated stenosis 782, the stent delivery catheter826 can be removed after which the occlusion balloon 711 can be deflatedfollowed by deflation of the proximal balloon 661 in the mannerhereinbefore described. Also it should be appreciated that if desired inconnection with the deployment of the stent delivery catheter 826 beforeit is removed but after deflation of its balloon (not shown), it may bedesirable to again flush the working space or chamber 803 between theocclusion balloons 669 and 711 of emboli which may be dislodged duringthe delivery and deployment of the stent. The irrigation catheter 766can be deployed in the same manner as hereinbefore described with asaline irrigation solution supplied to the working space 803 in themanner hereinbefore described and liquid aspirated therefrom by the useof the bulb 821 in the manner hereinbefore described.

Heretofore the apparatus of the present invention has been utilized forperforming a procedure on a saphenous vein graft where there are nobranches to be dealt with. An apparatus incorporating the presentinvention also can be useful in connection with vessels in a human beinghaving branches therein, as for example the carotids. For this purpose,a main catheter 831 (see FIG. 44) is provided which is very similar tothe main catheter 651 with the exception that the adapter 832 providedon the proximal extremity is provided with catheter ports 833 and 834which are in communication with the large central lumen 657 extendingthe length of the main catheter. The catheter ports 833 and 834 have aconstruction similar to the exchange catheter and therapeutic catheterport 692 hereinbefore described in connection with the main catheter651. These two catheter ports 833 and 834 are necessary because in acarotid procedure, two balloon-on-a-wire devices are utilized. The maincatheter should be larger, as for example as large as 12 French, toprovide a larger central lumen to accommodate the two balloon-on-a-wiredevices.

One of the balloon-on-a-wire devices can be substantially identical tothe balloon-on-a-wire device 701 described. The other balloon-on-a-wiredevice 835 as shown in FIG. 45 differs from the device 701 shown in FIG.30 in that in place of the removable valve attachment 741 there isprovided a fixed adapter 836 which consists of a body 837 provided withdiametrically extending wings 838 to facilitate grasping of the adapter836. The body 837 is provided with a bore 839 which is in communicationwith the lumen 706 in the guide wire 702. The adapter is provided with aLuer-type fitting 840 to provide a balloon inflation port.

Operation and use of the apparatus of the present invention inperforming a procedure in a carotid artery is shown in the cartoons inFIGS. 46-50. Let it be assumed that it is desired to perform a procedurewith the apparatus of the present invention on a carotid artery in apatient, as for example common carotid 841 which branches into anexternal carotid 842 and an internal carotid 843 and that there is anarrowing or a stenosis 844 in the internal carotid 843 near thebifurcation into the external and internal carotids 842 and 843. Themain catheter 831 can be introduced in the manner hereinbefore describedwith respect to a saphenous vein graft. For example it can be introducedthrough the femoral artery in the leg and then advanced into the aorticarch up into the common carotid 841 until the occlusion balloon 669carried thereby is near the bifurcation as shown in FIG. 46. Theocclusion balloon 669 is then inflated to at least one atmosphere asshown in FIG. 47 to form a seal to occlude the common carotid 841 and totemporarily stop the flow of blood to the face and brain of the patientthrough the common carotid 841 and to provide a working space 845 distalof the occlusion balloon 669. The inflation is accomplished by suitablemeans as for example a syringe 846 secured to the balloon inflationfitting 687. Thereafter, a balloon-on-a-wire device 831 of the typeshown in FIG. 45 is introduced through the catheter port 833 andadvanced through the central lumen 657 of the main catheter 831 afterwhich the distal extremity is guided into the external carotid 842 so itis disposed beyond the bifurcation. The occlusion balloon 711 carried bythe distal extremity is then inflated by suitable means such as asyringe 847 secured to the attachment 836 to occlude the externalcarotid. As hereinbefore pointed out, the balloon 711 is an occlusionballoon that typically is inflated to a suitable occlusion pressure asfor example one to two atmospheres.

Another balloon-on-a-wire device such as the balloon-on-a-wire device701 is then introduced through the catheter port 834 and advancedthrough the central passage or lumen 657 until it exits from the maincatheter 831 after which it is guided into the internal carotid 843 pastthe stenosis 844 so that the occlusion balloon 711 is distal of thestenosis 844. The occlusion balloon 711 is then inflated as shown by thedotted lines in FIG. 47 by the use of a syringe 848 secured to theinflation port carried by the removable valve attachment 741. Thus, thelimits of the working space or chamber 845 are defined by the occlusionballoons 669 and 711. As soon as the balloon 711 has been inflated, theballoon inflation lumen can be plugged in the manner hereinbeforedescribed by the use of a plug mandrel 756 (see FIG. 48). It should beappreciated even though the guide wire 702 and the occlusion balloon 711carried thereby may dislodge particles from the plaque forming thestenosis 844, the dislodged particles will not travel to the brainbecause the common carotid supplying blood to the internal carotid 843has been occluded by the occlusion balloon 669.

The removable valve attachment 741 can then be removed in the mannerhereinbefore described so that the proximal extremity of the guide wire702 is free of obstructions as shown in FIG. 48. Thereafter theirrigation catheter 766 can be introduced over the guide wire 702 andthence into the port 834 until its distal extremity extends beyond thedistal extremity of the main catheter 831. A therapeutic ballooncatheter 801 of the same type as hereinbefore described can then beintroduced through the irrigation catheter 766. It should be appreciatedthat if desired, the therapeutic balloon catheter can be preloaded intothe irrigation catheter 766 and the irrigation catheter 766 and thetherapeutic balloon catheter 801 can be introduced in unison. Assumingthat the irrigation catheter 766 has been introduced first, thetherapeutic balloon catheter 801 is introduced through the irrigationcatheter 766 until it extends beyond the distal extremity of theirrigation catheter 766 and is moved into the working space 845 untilthe therapeutic balloon 809 carried by the distal extremity thereof isin registration with the stenosis 844. The therapeutic balloon 809 isthen inflated as shown in FIG. 48 by the use of an inflation/deflationdevice 851 represented schematically by a syringe to a suitabletherapeutic pressure to compress the plaque forming the stenosis 844 todilate the stenosis to increase the size of the flow passage through thestenosis 844. The therapeutic balloon 809 can then be deflated. In theevent emboli 804 are created as hereinbefore described by the passage ofthe therapeutic balloon 809 through the stenosis, these emboli 804 canbe removed as shown in FIG. 49 by introducing a saline solution throughthe tube 819 and into the irrigation port 773 of the irrigation catheter766 to cause a saline solution to be discharged into the space formedbetween the two occlusion balloons 711 and 669. To achieve a moreeffective aspiration, the distal tip of the irrigation catheter 766 canbe moved through the stenosis 844 to just proximal of the occlusionballoon 711. Aspirate is removed through the aspiration port 689 throughthe use of the bulb 821 and the collection bag 824 to remove the salinesolution carrying with it the emboli 804 which may have been created anddeposit the same in the collection bag 824. This irrigation andaspiration can be carried on for a suitable period of time as forexample 5 to 30 seconds after which the occlusion balloons 711 in bothof the branches 842 and 843 can be deflated and the devices 701 and 835can be removed along with the catheter 801 carrying the therapeuticballoon 809. Similarly, the occlusion balloon 669 can be deflated topermit blood to flow into the common carotid 841 and the external andinternal carotids 842 and 843. Alternatively, the sequence of deflationof the balloons can be carried out in the manner hereinbefore describedin connection with a vessel without a bifurcation.

In the event it is desired to deliver a stent into the dilated stenosis844, this can be accomplished by reinflating the occlusion balloon 669and then reinflating the occlusion balloons 711 in both of the branchesafter which a balloon stent delivery catheter 826 of the typehereinbefore described can be delivered over the guide wire 702 in thesame manner as the therapeutic balloon catheter 766 and delivered intothe desired location and then deployed in the dilated stenosis 844.After the stent 827 has been deposited and the balloon of the stentdelivery catheter 826 is deflated, the irrigation and aspirationprocedures hereinbefore described can be repeated to remove any emboliwithin the space formed between the occlusion balloons 711 and 669. Thestent delivery catheter 826 can be removed. After a suitable period ofirrigation and aspiration, as for example 5 to 30 seconds, the occlusionballoon 711 can be deflated after which the occlusion balloon 669 can bedeflated and the balloon-on-a-wire devices 701 and 835 removed alongwith the main catheter 652.

From the foregoing it can be seen that there has been provided a new andimproved apparatus and a method for utilization of the same which makesit possible to carry out such stenosis opening procedures without theperfusion of blood. Complete stenosis procedures can be carried out in aperiod of time which is less than six minutes for each completeprocedure. Even though blood flow is occluded during this period oftime, this period of time is much less than the period of time, as forexample 30 minutes, required for a conventional endoatherectomy. Thus,the procedures of the present invention can be carried out withoutendangering the patient, as for example the brain or the heart of thepatient.

The desire to eliminate the use of a large guiding catheter for use withthe main catheter 651 was hereinbefore discussed. Also, it washereinbefore disclosed that the main catheter 651 can be insertedindependently through a conventional sheath (not shown) in the femoralartery and thereafter a smaller conventional guiding catheter 786 isintroduced through the main catheter so that its distal extremity 789 isin the vessel. In other procedures it may be desirable to carry thisconcept still further, i.e., eliminating the need for a large guidingcatheter and also the need for a smaller guiding catheter to be advancedthrough the main catheter. To do this, it may be desirable to provide adistal extremity on the main catheter 651 which is shaped in apredetermined manner. For example, in the main catheter 651 a shown inFIG. 26A there is provided in the distal extremity a conventionalJudkins left shape and in the main catheter 651 b shown in FIG. 26Bthere is provided in the distal extremity a conventional Judkins rightshape. Other than the shaping of the distal extremities as hereinbeforedescribed, the main catheters 651 a and 651 b are constructed in amanner very similar to the catheter 651 and are provided with occlusionballoons 669 as shown.

Since the main catheters 651 a and 651 b are relatively flexible, theycan be inserted into the femoral artery and have their distalextremities guided into the desired locations with the catheter beingselected for the appropriate bend to reach the desired location. Withthe main catheter having such capabilities, it is possible in connectionwith the present invention to advance the main catheter 651 into thedesired location by the use of a balloon-on-a-wire device of the typehereinbefore described, or alternatively over a conventional guide wire.This makes it possible to eliminate the use of a guiding catheter andtherefore substantially simplify the procedures of the present inventionand reduce the costs of such procedures.

In connection with the irrigation catheter 766 hereinbefore described inFIG. 36, it should be appreciated as shown in FIGS. 36A and 36B thatirrigation catheters 766 a and 766 b can be provided which have softdistal extremities to provide additional flexibility and trackabilityand thereby reduce trauma in vessels through which they are introduced.Thus in the irrigation catheter 766 a shown in FIG. 36A, the mainportion of the flexible elongate tubular member 767 which can beconsidered to be the shaft can have a greater stiffness than the distalportion 767 a of the distal extremity. This can be readily accomplishedby utilizing a plastic such as PEBAX® and HYTREL® of various desireddurometers. For example, the main shaft 767 can have a durometer rangingfrom 80-100 whereas the distal portion 767 a can have a durometerranging from 50-70. The cylindrical tip 767 c with a rounded forwardedge as shown is provided with a still lower durometer as for example35-55 durometer. Thus it can be seen that there has been provided anirrigation catheter which has a very soft tip and which has a distalportion in the distal extremity which is very flexible to permittracking and to reduce trauma.

In the irrigation catheter 766 b shown in FIG. 36, the shaft 767 canhave a durometer ranging from 80-100 whereas the portion 767 a can havea durometer ranging from 60-70 and which has a portion 767 b formed ofthe same durometer material that is inclined inwardly and distally toreduce the size of the opening for the passage or lumen 768 as shown.The tip 767 which can be formed of a low durometer as for example 35-55durometer is mounted on the distal extremity 767 b. In order to enhancethe flow of irrigation fluid from the lumen 768 a plurality of holes 857is circumferentially distributed around the portion 767 a to augment theflow of irrigation fluid other than through the passage 856. The use ofthe embodiments 766 a and 766 b of the irrigation catheter is verysimilar to that hereinbefore described with the irrigation catheter 766shown in FIG. 36. It should be appreciated that if differing stiffnessesare desired for the main catheters 651 and 831, the same concepts asdisclosed for the irrigation catheter 766 can be utilized by selectingmaterials having desired durometers for various portions of thecatheters.

Another embodiment of the balloon-on-a-wire device is shown in FIGS. 51and 52 in which the balloon-on-a wire device 901 is in many respectsvery similar to the balloon-on-a-wire device 701 shown in FIG. 30 ashereinbefore described. The balloon-on-a-wire device 901 consists of aflexible elongate member in the form of a guide wire 702 having proximaland distal extremities 703 and 704 with a lumen 706 extendingtherethrough. A removable valve attachment or fitting 741 is provided onthe proximal extremity 907. A plug mandrel 756 is carried by theremovable valve attachment 741 for use in plugging the bore 706 whennecessary. An elastomeric balloon 906 is provided on the distalextremity 704 and is provided with proximal and distal extremities 907and 908. The balloon 906 has a suitable length as for example 10millimeters and a suitable diameter when collapsed or deflated of 1 mm.In order that the balloon 906 assume a generally rectangular shape asviewed in cross-section as shown in FIG. 51 with generally right anglecorners, the balloon 906 is provided with spaced-apart cylindricalregions 906 a and 906 b of greater thickness than an intermediateportion 906 c. For example, portions 906 a and 906 b can have athickness of 0.006″ to 0.010″ and portion 906 c of 0.003″ wallthickness. Such a balloon when inflated will have a squareness asillustrated by the dotted lines in FIG. 51. This squareness of theballoon corners helps to assure that emboli will not become entrappedbetween the balloon and the vessel wall and thereby will not roll by theballoon as it is moved in the vessel.

An elongate slot 911 is ground into the distal extremity of the guidewire 702 to a suitable depth which is in excess of one half of thediameter of the guide wire 702. The slot 911 is in communication withthe lumen 706 and opens into the interior of the balloon 906. A taperedcore wire 913 is mounted in the distal extremity 704 of the guide wire702. The core wire 913 is provided with a portion 913 a which has aprogressive decrease in diameter extending from the proximal extremityto a portion 913 b which is generally of a uniform diameter of asuitable size, as for example 0.003″ and is formed into a bend 916 andextends proximally along the slot 916 and proximally thereof where it issecured to the guide wire 702 by suitable means such as an adhesive 918.A coil spring 921 formed of a suitable material such as stainless steelor platinum extends over the slot 911 and proximally and distally of theslot 911 and is secured thereto by suitable means as solder 922.Positioned in this manner, the coil 921 generally circumscribes theinner circumference of the balloon 906 and serves to protect the balloon906 from any sharp edges as for example sharp edges formed by the slot911 in the coil wire 702. A tip coil 926 formed of a suitable radiopaquematerial such as a platinum or a platinum alloy is mounted over thedistal extremity of the guide wire 702 and secured thereto by suitablemeans such as solder 927. The distal extremity of the tip coil 926 whichmay have a suitable length, as for example 3 mm, is bonded to the corewire 913 b by a solder 928 which encloses the bend 916 and provides arounded forwardly protruding surface 929. The distal extremity 908 ofthe balloon 906 is secured to the coils 921 and 926 by an adhesive 931.Similarly, the proximal extremity 907 of the balloon 906 is secured tothe guide wire 702 and the portion 913 b by an adhesive 932.

The balloon-on-a-wire device 901 can be utilized in the same manner asthe balloon-on-a-wire device 701 hereinbefore described. It is believedthat the balloon-on-a-wire device 901 has several desirable features.For example the balloon 906 is protected from any sharp edges by thecoil spring 921. The slot 911, in addition to providing a means forinflating the balloon, also serves to provide a progressive weakening ofthe distal extremity of the guide wire 702 to impart additionalflexibility to the distal extremity of the device.

By utilizing a balloon-on-a-wire constructions herein disclosed, it ispossible to reduce the overall size of the apparatus for the procedures.In view of the fact that guide wires having a size of 0.014″ to 0.018″are utilized in the present invention, many conventional therapeuticballoon devices can be utilized by advancing the same over such sizeguide wires. By the provision of removable valve attachments for theballoon-on-a-wire devices, it is possible to use such devices forproviding the one or more balloons necessary for a procedure while atthe same time making it possible to utilize such devices as guide wiresafter removing the removable valve attachments on the proximalextremities. This makes it possible to utilize conventional stentdelivery catheters, ultrasound catheters and the like by advancing themover the already in place guide wires.

It should be appreciated that it may be possible to eliminate the use ofthe occlusion balloons 711 which are distal of the proximal ballooncarried by the main catheter and distal of the stenosis, since bloodflow is occluded during the time that the occlusion balloon 669 isinflated.

Another embodiment of a catheter apparatus incorporating the presentinvention for treating occluded vessels is shown in FIGS. 53 and 54. Asshown therein, the catheter apparatus 951 consists of a flexibleelongate member 952 similar to those hereinbefore described which isprovided with proximal and distal extremities 953 and 954. Aconventional adapter 956 is mounted on the proximal extremity and isprovided with a Tuohy-Borst fitting 957 which is in communication with alarge central lumen 958 extending from the proximal extremity 953 to thedistal extremity 954. An aspiration fitting 961 is provided on theadapter 956 as well as an irrigation fitting 962, both of which are incommunication with the central lumen 958. However, it should beappreciated that if desired separate lumens can be provided in theflexible elongate member 952 for both of the fittings 961 and 962.

Self-expanding sealing means 966 is mounted on the distal extremity 954.This self-expanding sealing means 966 can take any suitable form. Forexample, as shown it can consist of a braided structure 967 formed of asuitable shape memory material such as a nickel titanium alloy that willattempt to expand to a predetermined shape memory. Other than shapememory materials, other materials such as stainless steel, titanium orother materials can be utilized in the braid 967 as long as they havethe capability of expanding when the self-expanding seal means isreleased. Also it should be appreciated that the self-expanding sealmeans 966 can be comprised of an absorbent material which when itabsorbs saline or blood expands to form a seal. Such seals can bereadily accomplished because it is only necessary to form a seal ofapproximately one atmosphere to prevent small particles from movingdownstream.

In order to prevent abrasion of a vessel, it is desirable to cover thebraided structure 967 with a covering 968 of a suitable material such asa polymer which extends over the braided structure 967 and which moveswith the braided structure 967 as it expands and contracts. The polymercan be of a suitable material such as silicone, C-FLEX®, polyethylene orPET which would form a good sealing engagement with the wall of theartery.

Means is provided for compressing the self-expanding sealing means 966so that the apparatus can be inserted into the vessel 781 and consistsof an elongate sleeve 1071 having proximal and distal extremities 1072and 1073 and a bore 1074 extending from the proximal extremity 1072 tothe distal extremity 1073. A collar 1076 is mounted on the proximalextremity 1072 of the sleeve 1071 and is positioned near the adapter956. The collar 1076 serves as means for retracting the sleeve as shownin FIG. 54 to uncover the self-expanding sealing means 966 after thecatheter has been deployed to permit the self-expanding sealing means966 to expand and form a seal with the arterial vessel adjacent thestenosis to be treated.

Another embodiment of a catheter apparatus for treating occluded vesselsincorporating the present invention is shown in FIGS. 55 and 56. Asshown therein, the apparatus 1081 consists of a guiding catheter 1082having proximal and distal extremities 1083 and 1084. As shown, thedistal extremity 1083 is provided with a pre-formed bend of aconventional type. A conventional attachment 1086 is mounted on theproximal extremity 1083. Self-expanding seal means 1091 is mounted onthe distal extremity 1084 and is of the type hereinbefore described inconnection with the embodiments shown in FIGS. 53 and 54. A sleeve 1096similar to the sleeve 1071 of the previous embodiment is provided in thepresent embodiment for encasing the self-expanding seal means 1091 andfor releasing the same after it has been disposed in an appropriateposition within a vessel adjacent the occlusion to be treated. Thus asleeve 1096 is provided having proximal and distal extremities 1097 and1098 and having a bore 1099 extending from the proximal extremity to thedistal extremity which is sized so that it can receive the guidecatheter 1082. It is provided with a collar 1101 on its proximalextremity which is adapted to be disposed outside the patient and whichis adapted to be grasped by the physician for pulling the sleeve 1096proximally to uncover the self-expanding seal 1091 after the apparatushas been deployed to permit the self-expansion of the sealing means 1091to form a seal with the vessel wall is shown in FIG. 56.

In accordance with the hereinbefore described descriptions, it isapparent that the apparatus can be readily deployed and serve the samefunction as the main catheter. To accomplish this, the assembly 1081 canbe introduced into the femoral artery and the distal extremity advancedinto the desired location in the arterial vessel. After it has beenproperly positioned, the physician can retract the sleeve 1096 to permitthe self-expanding seal means 1091 to expand and to form a seal with thewall of the arterial vessel to occlude the arterial vessel and interruptthe flow of blood in the vessel to provide a working space distal of theocclusion formed. This prevents small particles which may thereafter bedislodged from moving downstream. Since a central lumen is available,the therapeutic procedures hereinbefore described can be employed withthe catheter apparatus shown in FIGS. 53, 54, 55 and 56.

Thus it can be seen that it has been possible to substantially reducethe complexity of the apparatus utilized in such procedures. Thisreduces the cost of the apparatus used therein as well as reducing thetime required for performing such procedures making the procedures lesscostly.

It will be appreciated that certain variations of the present inventionmay suggest themselves to those skilled in the art. The foregoingdetailed description is to be clearly understood as given by way ofillustration, the spirit and scope of this invention being limitedsolely by the appended claims.

1. A method of protecting a patient from embolization during apercutaneous procedure on a vessel, comprising the steps of: providing aflexible elongate member having proximal and distal ends, a proximal anda distal region, an expandable member associated with the distal region,and a removable sheath which covers the expandable member and isslidable over the flexible elongate member; introducing the distal endof the flexible elongate member into the patient's vessel with thesheath covering the expandable member, and positioning the expandablemember downstream of a region of interest, wherein the sheath andflexible elongate member cross the region of interest; sliding thesheath toward the proximal end of the flexible elongate member touncover the expandable member and deploy the expandable member;advancing over the flexible elongate member a stent-deployment catheterto the region of interest; and expanding a stent at the region ofinterest, wherein embolic material is generated and captured before theexpandable member is removed from the patient's vessel.
 3. The method ofclaim 1, wherein the stent is deployed by inflation of a balloon.
 5. Themethod of claim 1, wherein the expandable member comprises a braidedstructure.
 6. The method of claim 1, wherein the expandable memberincludes a covering.
 7. The method of claim 1, wherein the expandablemember is self-expanding.
 9. A percutaneous system, comprising: aflexible elongate member having proximal and distal ends, a proximal anddistal region, and an expandable member associated with the distalregion; a sheath which is shaped to receive the flexible elongate memberand retain the expandable member in a contracted condition, and toslidably release the expandable member to an expanded condition when thesheath moves toward the proximal end of the flexible elongate member; acatheter having a proximal and a distal end, a proximal and a distalregion, and a lumen which slidably receives the flexible elongatemember; and an expandable stent disposed about the distal region of thecatheter, the stent having a first diameter which permits intraluminaldelivery of the stent into a body passageway and which places the stentin close proximity to the catheter, and having a second expandeddiameter adapted to substantially engage a wall of the body passageway,wherein, during use, the flexible elongate member is positioned across aregion of interest, the expandable member is expanded, and the stent isdeployed within the region of interest and remains in place afterremoval of the catheter from the vessel.
 10. The system of claim 9wherein the expandable member comprises a braided structure and acovering over the braided structure.
 11. The system of claim 10, whereinthe braided structure is self-expanding.
 18. The system of claim 9,wherein the stent and the expandable member are self-expanding.
 19. Thesystem of claim 9, wherein the stent is removable.
 20. The system ofclaim 9, wherein the stent is self-expanding.
 22. The system of claim 9,wherein the stent comprises a nickel-titanium alloy material.
 23. Thesystem of claim 9, wherein the stent is cylindrically-shaped.
 25. Amethod of protecting a patient from embolization during a percutaneousprocedure on a vessel, comprising the steps of: providing a guidewirehaving proximal and distal ends, a proximal and a distal region, anexpandable filter associated with the distal region, and a removablesheath which covers the expandable filter and is slidable over theguidewire; introducing the distal end of the guidewire into thepatient's vessel with the sheath covering the expandable filter, andpositioning the filter downstream of a region of interest, wherein thesheath and guidewire cross the region of interest; sliding the sheathtoward the proximal end of the guidewire and removing the sheath fromthe vessel, wherein the expandable filter is uncovered; deploying thefilter; advancing over the guidewire a stent-deployment catheter to theregion of interest; and expanding the stent at the region of interest,wherein embolic material is generated and captured before the expandablefilter is removed from the patient's vessel.
 26. A percutaneous systemhaving filter and stent deployment capabilities, comprising: a guidewirehaving proximal and distal ends, a proximal and distal region, and anexpandable filter associated with the distal region; a sheath which isshaped to receive the guidewire and retain the filter in a contractedcondition, and to slideably release the filter to an expanded conditionwhen the sheath moves toward the proximal end of the guidewire; acatheter having a proximal and a distal end, a proximal and a distalregion, and a lumen which slideably receives the guidewire; and anexpandable stent disposed about the distal region of the catheter, thestent having a first diameter which permits intraluminal delivery of thestent into a body passageway and which places the stent in closeproximity to the catheter, and having a second expanded diameter adaptedto substantially engage a wall of the body passageway, wherein, duringuse, the guidewire is positioned across a region of interest, the filteris expanded, and the stent is deployed within the region of interest andremains in place after removal of the catheter from the vessel.
 27. Amethod of protecting a patient from embolization during a percutaneousprocedure on a vessel, comprising the steps of: providing a flexibleelongate member having proximal and distal extremities, a self-expandingmember mounted on the distal extremity, and a sleeve covering andcompressing the self-expanding member; advancing the distal extremity ofthe flexible elongate member and the sleeve into the patient's vesseland positioning the self-expanding member adjacent to a stenosis to betreated; retracting the sleeve toward the proximal end of the flexibleelongate member to uncover the self-expanding member and to permit theself-expanding member to expand to a vessel wall adjacent to thestenosis; advancing a stent delivery catheter carrying a stent thereonto the stenosis; and expanding the stent at the stenosis while theself-expanding member is expanded, wherein emboli which may be dislodgedduring the delivery and expanding of the stent are captured before theself-expanding member is removed from the patient's vessel.
 28. Themethod of claim 27, wherein the stent-delivery catheter is advanced inco-axial relationship relative to the flexible elongate member.
 29. Themethod of claim 27, wherein the self-expanding member is braided. 30.The method of claim 27, wherein the self-expanding member is made of ashape memory material.
 31. The method of claim 27, wherein theself-expanding member is made of a nickel titanium alloy.
 32. Apercutaneous system having stent deployment capabilities, comprising: aflexible elongate member having proximal and distal extremities and aself-expanding member mounted on the distal extremity; a sleeve having aproximal and distal extremity, the sleeve having a bore to receive theflexible elongate member and to cover and compress the self-expandingmember, the sleeve being retractable to uncover the self-expandingmember to permit the self-expanding member to expand into engagementwith a vessel wall adjacent to a stenosis to be treated; and a stentdelivery catheter having a flexible shaft and a lumen; and an expandablestent carried on the stent delivery catheter, wherein, during use, theself expanding member is positioned and expanded adjacent to a stenosisto be treated and the stent is deployed at the stenosis and remains inplace after removal of the stent delivery catheter.
 33. The percutaneoussystem of claim 32, wherein the sleeve further comprises a collarmounted on the proximal extremity of the sleeve whereby the sleeve maybe retracted to uncover the self-expanding member to permit theself-expanding member to expand to the vessel adjacent the stenosis tobe treated.
 34. The percutaneous system of claim 32, wherein theself-expanding member is braided.
 35. The percutaneous system of claim32, wherein the self-expanding member is made of a shape memorymaterial.
 36. The percutaneous system of claim 35, wherein theself-expanding member is made of a nickel titanium alloy.
 37. Thepercutaneous system of claim 32, wherein the stent is self-expanding.38. A method of protecting a patient from embolization during apercutaneous procedure on a vessel, comprising the steps of: providing aflexible elongate member having proximal and distal extremities, abraided structure mounted on the distal extremity, and an elongatesleeve which covers the braided structure; advancing the distalextremity of the flexible elongate member into the patient's vessel withthe elongate sleeve covering the braided structure, and positioning theelongate sleeve and flexible elongate member such that the elongatesleeve and flexible elongate member cross a region of interest;retracting the elongate sleeve toward the proximal end of the flexibleelongate member, wherein the braided structure is uncovered; advancingover the flexible elongate member a stent delivery catheter to theregion of interest; and deploying a stent at the region of interest,wherein embolic material is generated and captured before the braidedstructure is removed from the patient's vessel.
 39. A percutaneoussystem having stent deployment capabilities, comprising: a flexibleelongate member having proximal and distal extremities and a braidedstructure mounted on the distal extremity; an elongate sleeve having abore to receive the flexible elongate member and retain the braidedstructure in a compressed condition, and is retractable toward theproximal end of the flexible elongate member to release the braidedstructure to an expanded condition; a catheter having a flexible shaftand a lumen; and an expandable stent carried on the catheter, wherein,during use, the flexible elongate member is positioned adjacent astenosis to be treated, the braided structure is expanded, and the stentis deployed at the stenosis and remains in place after removal of thecatheter from the vessel.
 40. A method of protecting a patient fromembolization during a percutaneous procedure on a vessel, comprising thesteps of: providing a flexible elongate member having proximal anddistal ends, a proximal and a distal region, an expandable memberassociated with the distal region, and a sleeve which covers theexpandable member; introducing the distal end of the flexible elongatemember into the patient's vessel with the sleeve covering the expandablemember, and positioning the expandable member adjacent to a region ofinterest to be treated; retracting the sleeve toward the proximal end ofthe flexible elongate member to uncover the expandable member and deploythe expandable member; advancing a stent-delivery catheter to the regionof interest; and expanding a stent at the region of interest, whereinembolic material generated during the procedure is captured before theexpandable member is removed from the patient's vessel.
 41. The methodof claim 40, wherein the expandable member comprises a filter.
 42. Themethod of claim 40, wherein the expandable member comprises a braidedstructure.
 43. The method of claim 40, wherein the expandable member isself-expanding.
 44. The method of claim 40, wherein the flexibleelongate member comprises a guidewire.
 45. The method of claim 40,wherein the region of interest comprises a stenosis.
 46. The method ofclaim 40, wherein the stent-delivery catheter is delivered over theflexible elongate member to the region of interest.
 47. The method ofclaim 40, wherein the expandable member is positioned downstream of theregion of interest, wherein the sleeve and the expandable member crossthe region of interest.
 48. A percutaneous system, comprising: aflexible elongate member having proximal and distal ends, a proximal anddistal region, and an expandable member associated with the distalregion; a sleeve having a proximal and distal extremity, wherein thesleeve is adapted to receive the flexible elongate member and to coverthe expandable member, and wherein the sleeve is adapted to retract touncover the expandable member to permit the expandable member to expandadjacent to a region of interest; and a stent delivery catheter having aflexible shaft and a lumen; and an expandable stent carried by the stentdelivery catheter, wherein the expandable member is positionable andexpandable adjacent to the region of interest, and wherein the stent isdeployable at the region of interest and able to remain in place afterremoval of the stent delivery catheter.
 49. The percutaneous system ofclaim 48, wherein the expandable member comprises a filter.
 50. Thepercutaneous system of claim 48, wherein the expandable member comprisesa braided structure.
 51. The percutaneous system of claim 48, whereinthe expandable member is adapted to expand into engagement with a vesselwall.
 52. The percutaneous system of claim 48, wherein the expandablemember is self-expanding.
 53. The percutaneous system of claim 48,wherein the sleeve comprises a bore to receive the flexible elongatemember.
 54. The percutaneous system of claim 48, wherein the region ofinterest comprises a stenosis.
 55. The percutaneous system of claim 48,wherein the expandable stent has a first diameter which permitsintraluminal delivery of the stent into a body passageway and whichpermits placement of the stent in close proximity to the catheter, andwherein the stent has a second expanded diameter adapted tosubstantially engage a wall of the body passageway.
 56. The percutaneoussystem of claim 48, wherein the flexible elongate member comprises aguidewire.
 57. The percutaneous system of claim 48, wherein the flexibleelongate member is positionable across a region of interest with theexpandable member expanded and the stent deployed within the region ofinterest.
 58. The percutaneous system of claim 48, wherein the lumenslideably receives the flexible elongate member.
 59. The percutaneoussystem of claim 48, wherein the expandable member is a self-expandingbraided filter and the flexible elongate member is a guidewire.